@article{LilieBaerKettneretal.2011,
  author    = {Lilie, Hauke and Baer, Dorit and Kettner, Karina and Weininger, Ulrich and Balbach, Jochen and Naumann, Manfred and Mueller, Eva-Christina and Otto, Albrecht and Gast, Klaus and Golbik, Ralph and Kriegel, Thomas},
  title     = {Yeast hexokinase isoenzyme ScHxk2 stability of a two-domain protein with discontinuous domains},
  series = {Protein engineering design \& selection},
  volume    = {24},
  journal   = {Protein engineering design \& selection},
  number    = {1-2},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  issn      = {1741-0126},
  doi       = {10.1093/protein/gzq098},
  pages     = {79 -- 87},
  year      = {2011},
  abstract  = {The hexokinase isoenzyme 2 of Saccharomyces cerevisiae (ScHxk2) represents an archetype of a two-domain protein with the active site located in a cleft between the two domains. Binding of the substrate glucose results in a rigid body movement of the two domains leading to a cleft closure of the active site. Both domains of this enzyme are composed of discontinuous peptide sequences. This structural feature is reflected in the stability and folding of the ScHxk2 protein. Structural transitions induced by urea treatment resulted in the population of a thermodynamically stable folding intermediate, which, however, does not correspond to a molecule with one domain folded and the other unfolded. As demonstrated by different spectroscopic techniques, both domains are structurally affected by the partial denaturation. The intermediate possesses only 40\% of the native secondary structural content and a substantial increase in the Stokes radius as judged by circular dichroism and dynamic light scattering analyses. One-dimensional H-1 NMR data prove that all tryptophan residues are in a non-native environment in the intermediate, indicating substantial changes in the tertiary structure. Still, the intermediate possesses quite a high stability for a transition intermediate of about Delta G = -22 kJ mol(-1).},
  language  = {en}
}
@article{LilieBaerKettneretal.2011,
  author    = {Lilie, Hauke and B{\"a}r, Dorit and Kettner, Karina and Weininger, Ulrich and Balbach, Jochen and Naumann, Manfred and M{\"u}ller, Eva-Christina and Otto, Albrecht and Gast, Klaus and Golbik, Ralph},
  title     = {Yeast hexokinase isoenzyme ScHxk2 : stability of a two-domain protein with discontinuous domains},
  issn      = {0269-2139},
  year      = {2011},
  abstract  = {The hexokinase isoenzyme 2 of Saccharomyces cerevisiae (ScHxk2) represents an archetype of a two-domain protein with the active site located in a cleft between the two domains. Binding of the substrate glucose results in a rigid body movement of the two domains leading to a cleft closure of the active site. Both domains of this enzyme are composed of discontinuous peptide sequences. This structural feature is reflected in the stability and folding of the ScHxk2 protein. Structural transitions induced by urea treatment resulted in the population of a thermodynamically stable folding intermediate, which, however, does not correspond to a molecule with one domain folded and the other unfolded. As demonstrated by different spectroscopic techniques, both domains are structurally affected by the partial denaturation. The intermediate possesses only 40\% of the native secondary structural content and a substantial increase in the Stokes radius as judged by circular dichroism and dynamic light scattering analyses. One-dimensional 1H NMR data prove that all tryptophan residues are in a non-native environment in the intermediate, indicating substantial changes in the tertiary structure. Still, the intermediate possesses quite a high stability for a transition intermediate of about ;G = ;22 kJ mol;1.},
  language  = {en}
}
@article{FabianGastFilimonovetal.2005,
  author    = {Fabian, H. and Gast, Klaus and Filimonov, Vladimir V. and Zamyatkin, D. F. and Rogov, V. V.},
  title     = {Thermal unfolding of two designed monomeric lambda Cro repressor variants},
  issn      = {0924-2031},
  year      = {2005},
  abstract  = {The thermal unfolding of the wild-type lambda Cro repressor and of two designed variants, Cro K56-[DGEVK] and Cro K56-[DGEVK] Q16L, was studied by Fourier transform infrared spectroscopy and dynamic light scattering. The engineered Cro K56-[DGEVK] monomer has five additional amino acids inserted after position 56 of the wild-type sequence, while the K56-[DGEVK] Q16L variant differs only in one position (Gln-16 to Leu substitution) from the Cro K56-[DGEVK] sequence. The temperature dependence of selected protein backbone infrared `marker' bands revealed that Cro K56- [DGEVK] is slightly more stable than the wild-type protein, while the replacement of Gln-16 by Leu increases the thermal transition temperature by similar to 20 degrees C. Moreover, thermal unfolding of the two Cro variants was found to proceed through equilibrium unfolding intermediates and to involve the formation of oligomers. The first thermal transition of Cro K56-[DGEVK] involves the melting of major parts of its native secondary structure and is accompanied by the formation of dinners and non-native beta-sheet structures. These structures unfold during a second transition at higher temperatures, accompanied by the dissociation of the dimers. In contrast to the Cro K56-[DGEVK] protein, the intermediate state of the Cro K56-[DGEVK] Q16L variant is less well defined, and involves the formation of oligomers of different size. (c) 2005 Elsevier B.V. All rights reserved},
  language  = {en}
}
@article{WalterRueckertVossetal.2009,
  author    = {Walter, Juliane K. and R{\"u}ckert, Christine and Voss, Martin and M{\"u}ller, Sebastian L. and Piontek, Joerg and Gast, Klaus and Blasig, Ingolf E.},
  title     = {The oligomerization of the coiled coil-domain of occluddin is redox sensitive},
  issn      = {0077-8923},
  doi       = {10.1111/j.1749-6632.2009.04058.x},
  year      = {2009},
  abstract  = {The transmembrane tight junction protein occludin is sensitive to oxidative stress. Occludin oligomerizes; however, its function in the tight junction is unknown. The cytosolic C-terminal tail contains a coiled coil-domain and forms dimers contributing to the oligomerization. The regulation of the oligomerization remains unclear. As the domain area contains sulfhydryl residues, we tested the hypothesis that the dimerization of the coiled coil-domain depends on these residues. We showed that the dimerization is modulated by the thiol concentration in the low-millimolar range, which is relevant both for physiological and pathophysiological conditions. Masking the sulfhydryl residues in the fragment by covalent binding of 4-vinyl pyridine prevented the dimerization but did not affect its helical structure and cylindric shape. The data demonstrate, for the first time, that disulfide bridge formation of murine cystein 408 is involved in the dimerization. This process is redox-sensitive but the secondary structure of the domain is not. It is concluded that the dimerization of occludin may play a regulatory role in the tight junction assembly under physiological and pathological conditions.},
  language  = {en}
}
@article{HanischVanRossumXieetal.2004,
  author    = {Hanisch, Uwe-Karsten and Van Rossum, Denise and Xie, Yiheng and Misselwitz, Rolf and Auriola, Seppo and Goldstein, Gundars and Koistinaho, Jari and Kettemann, Helmut and M{\"o}ller, Thomas and Gast, Klaus},
  title     = {The microglia-activating potential of thrombin : the protease is not involved in the induction of proinflammatory cytokines and chemokines},
  year      = {2004},
  abstract  = {The serine protease thrombin is known as a blood coagulation factor. Through limited cleavage of proteinase- activated receptors it can also control growth and functions in various cell types, including neurons, astrocytes, and microglia ( brain macrophages). A number of previous studies indicated that thrombin induces the release of proinflammatory cytokines and chemokines from microglial cells, suggesting another important role for the protease beyond hemostasis. In the present report, we provide evidence that this effect is not mediated by any proteolytic or non- proteolytic mechanism involving thrombin proper. Inhibition of the enzymatic thrombin activity did not affect the microglial release response. Instead the cyto-/chemokine-inducing activity solely resided in a high molecular weight protein fraction that could be isolated in trace amounts even from apparently homogenous alpha- and gamma-thrombin preparations. High molecular weight material contained thrombin-derived peptides as revealed by mass spectrometry but was devoid of thrombin-like enzymatic activity. Separated from the high molecular weight fraction by fast protein liquid chromatography, enzymatically intact alpha- and gamma-thrombin failed to trigger any release. Our findings may force a revision of the notion that thrombin itself is a direct proinflammatory release signal for microglia. In addition, they could be relevant for the study of other cellular activities and their assignment to this protease},
  language  = {en}
}
@article{HanischvanRossumGastetal.2004,
  author    = {Hanisch, Uwe-Karsten and van Rossum, D. and Gast, Klaus and Misselwitz, Rolf and Goldstein, Gundars and Koistinaho, Jari and M{\"o}ller, Thomas},
  title     = {The microglia-activating potential of thrombin : is the protease able to induce cyto- and chemokines?},
  year      = {2004},
  language  = {en}
}
@article{GastModler2005,
  author    = {Gast, Klaus and Modler, Andreas Johannes},
  title     = {Studying protein folding and aggregation by LASER light scattering},
  isbn      = {3-527-30784-2},
  year      = {2005},
  language  = {en}
}
@article{NettelsMuellerSpaethKuesteretal.2009,
  author    = {Nettels, Daniel and M{\"u}ller-Sp{\"a}th, Sonja and K{\"u}ster, Frank and Hofmann, Hagen and Haenni, Domminik and R{\"u}egger, Stefan and Reymond, Luc and Hoffmann, Armin S. and Kubelka, Jan and Heinz, Benjamin and Gast, Klaus and Best, Robert B. and Schuler, Benjamin},
  title     = {Single-molecule spectroscopy of the temperature-induced collapse of unfolded proteins},
  issn      = {0027-8424},
  year      = {2009},
  abstract  = {We used single-molecule FRET in combination with other biophysical methods and molecular simulations to investigate the effect of temperature on the dimensions of unfolded proteins. With singlemolecule FRET, this question can be addressed even under nearnative conditions, where most molecules are folded, allowing us to probe a wide range of denaturant concentrations and temperatures. We find a compaction of the unfolded state of a small cold shock protein with increasing temperature in both the presence and the absence of denaturant, with good agreement between the results from single-molecule FRET and dynamic light scattering. Although dissociation of denaturant from the polypeptide chain with increasing temperature accounts for part of the compaction, the results indicate an important role for additional temperaturedependent interactions within the unfolded chain. The observation of a collapse of a similar extent in the extremely hydrophilic, intrinsically disordered protein prothymosin suggests that the hydrophobic effect is not the sole source of the underlying interactions. Circular dichroism spectroscopy and replica exchange molecular dynamics simulations in explicit water show changes in secondary structure content with increasing temperature and suggest a contribution of intramolecular hydrogen bonding to unfolded state collapse.},
  language  = {en}
}
@article{WolffSchuelerGastetal.2020,
  author    = {Wolff, Martin and Sch{\"u}ler, Anja and Gast, Klaus and Seckler, Robert and Evers, Andreas and Pfeiffer-Marek, Stefania and Kurz, Michael and Nagel, Norbert and Haack, Torsten and Wagner, Michael and Thalhammer, Anja},
  title     = {Self-Assembly of Exendin-4-Derived Dual Peptide Agonists is Mediated by Acylation and Correlated to the Length of Conjugated Fatty Acyl Chains},
  series = {Molecular pharmaceutics},
  volume    = {17},
  journal   = {Molecular pharmaceutics},
  number    = {3},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1543-8384},
  doi       = {10.1021/acs.molpharmaceut.9b01195},
  pages     = {965 -- 978},
  year      = {2020},
  abstract  = {Dual glucagon-like peptide-1/glucagon receptor agonists have emerged as promising candidates for the treatment of diabetes and obesity. Issues of degradation sensitivity and rapid renal clearance are addressed, for example, by the conjugation of peptides to fatty acid chains, promoting reversible albumin binding. We use combined dynamic and static light scattering to directly measure the self-assembly of a set of dual peptide agonists based on the exendin-4 structure with varying fatty acid chain lengths in terms of apparent molecular mass and hydrodynamic radius (R-S). We use NMR spectroscopy to gain an insight into the molecular architecture of the assembly. We investigate conformational changes of the monomeric subunits resulting from peptide self-assembly and assembly stability as a function of the fatty acid chain length using circular dichroism and fluorescence spectroscopy. Our results demonstrate that self-assembly of the exendin-4-derived dual agonist peptides is essentially driven by hydrophobic interactions involving the conjugated acyl chains. The fatty acid chain length affects assembly equilibria and the assembly stability, although the peptide subunits in the assembly retain a dynamic secondary structure. The assembly architecture is characterized by juxtaposition of the fatty acyl side chains and a hydrophobic cluster of the peptide moiety. This cluster experiences local conformational changes in the assembly compared to the monomeric unit leading to a reduction in solvent exposure. The N-terminal half of the peptide and a C-terminal loop are not in contact with neighboring peptide subunits in the assemblies. Altogether, our study contributes to a thorough understanding of the association characteristics and the tendency toward self-assembly in response to lipidation. This is important not only to achieve the desired bioavailability but also with respect to the physical stability of peptide solutions.},
  language  = {en}
}
@article{WolffSchuelerGastetal.2020,
  author    = {Wolff, Martin and Sch{\"u}ler, Anja and Gast, Klaus and Seckler, Robert and Evers, Andreas and Pfeiffer-Marek, Stefania and Kurz, Michael and Nagel, Norbert and Haack, Torsten and Wagner, Michael and Thalhammer, Anja},
  title     = {Self-Assembly of Exendin-4-Derived Dual Peptide Agonists is Mediated by Acylation and Correlated to the Length of Conjugated Fatty Acyl Chains},
  series = {Molecular pharmaceutics},
  volume    = {17},
  journal   = {Molecular pharmaceutics},
  number    = {3},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1543-8384},
  doi       = {10.1021/acs.molpharmaceut.9b01195},
  pages     = {965 -- 978},
  year      = {2020},
  abstract  = {Dual glucagon-like peptide-1/glucagon receptor agonists have emerged as promising candidates for the treatment of diabetes and obesity. Issues of degradation sensitivity and rapid renal clearance are addressed, for example, by the conjugation of peptides to fatty acid chains, promoting reversible albumin binding. We use combined dynamic and static light scattering to directly measure the self-assembly of a set of dual peptide agonists based on the exendin-4 structure with varying fatty acid chain lengths in terms of apparent molecular mass and hydrodynamic radius (R-S). We use NMR spectroscopy to gain an insight into the molecular architecture of the assembly. We investigate conformational changes of the monomeric subunits resulting from peptide self-assembly and assembly stability as a function of the fatty acid chain length using circular dichroism and fluorescence spectroscopy. Our results demonstrate that self-assembly of the exendin-4-derived dual agonist peptides is essentially driven by hydrophobic interactions involving the conjugated acyl chains. The fatty acid chain length affects assembly equilibria and the assembly stability, although the peptide subunits in the assembly retain a dynamic secondary structure. The assembly architecture is characterized by juxtaposition of the fatty acyl side chains and a hydrophobic cluster of the peptide moiety. This cluster experiences local conformational changes in the assembly compared to the monomeric unit leading to a reduction in solvent exposure. The N-terminal half of the peptide and a C-terminal loop are not in contact with neighboring peptide subunits in the assemblies. Altogether, our study contributes to a thorough understanding of the association characteristics and the tendency toward self-assembly in response to lipidation. This is important not only to achieve the desired bioavailability but also with respect to the physical stability of peptide solutions.},
  language  = {en}
}
@article{WalterCastroVossetal.2009,
  author    = {Walter, Juliane K. and Castro, Victor Manuel and Voss, Martin and Gast, Klaus and Rueckert, Christine and Piontek, J{\"o}rg and Blasig, Ingolf E.},
  title     = {Redox-sensitivity of the dimerization of occludin},
  issn      = {1420-682X},
  doi       = {10.1007/s00018-009-0150-z},
  year      = {2009},
  abstract  = {Occludin is a self-associating transmembrane tight junction protein affected in oxidative stress. However, its function is unknown. The cytosolic C-terminal tail contains a coiled coil-domain forming dimers contributing to the self- association. Studying the hypothesis that the self-association is redox-sensitive, we found that the dimerization of the domain depended on the sulfhydryl concentration of the environment in low-millimolar range. Under physiological conditions, monomers and dimers were detected. Masking the sulfhydryl residues in the domain prevented the dimerization but affected neither its helical structure nor cylindric shape. Incubation of cell extracts containing full-length occludin with sulfhydryl reagents prevented the dimerization; a cysteine/alanine exchange mutant also did not show dimer formation. This demonstrates, for the first time, that disulfide bridge formation of the domain is involved in the occludin dimerization. It is concluded that the redox-dependent dimerization of occludin may play a regulatory role in the tight junction assembly under physiological and pathological conditions.},
  language  = {en}
}
@article{WalterCastroVossetal.2009,
  author    = {Walter, Juliane K. and Castro, Victor Manuel and Voss, M. and Gast, Klaus and Rueckert, C. and Piontek, J. and Blasig, Ingolf E.},
  title     = {Redox sensitivity of the dimerization of occludin},
  issn      = {1420-682X},
  year      = {2009},
  abstract  = {Occludin is a self-associating transmembrane tight junction protein affected in oxidative stress. However, its function is unknown. The cytosolic C-terminal tail contains a coiled coil-domain forming dimers contributing to the self- association. Studying the hypothesis that the self-association is redox-sensitive, we found that the dimerization of the domain depended on the sulfhydryl concentration of the environment in low-millimolar range. Under physiological conditions, monomers and dimers were detected. Masking the sulfhydryl residues in the domain prevented the dimerization but affected neither its helical structure nor cylindric shape. Incubation of cell extracts containing full-length occludin with sulfhydryl reagents prevented the dimerization; a cysteine/alanine exchange mutant also did not show dimer formation. This demonstrates, for the first time, that disulfide bridge formation of the domain is involved in the occludin dimerization. It is concluded that the redox-dependent dimerization of occludin may play a regulatory role in the tight junction assembly under physiological and pathological conditions.},
  language  = {en}
}
@article{GastSchuelerWolffetal.2017,
  author    = {Gast, Klaus and Sch{\"u}ler, Anja and Wolff, Martin and Thalhammer, Anja and Berchtold, Harald and Nagel, Norbert and Lenherr, Gudrun and Hauck, Gerrit and Seckler, Robert},
  title     = {Rapid-acting and human insulins},
  series = {Pharmaceutical research},
  volume    = {34},
  journal   = {Pharmaceutical research},
  number    = {795},
  publisher = {Springer},
  address   = {New York},
  issn      = {0724-8741},
  doi       = {10.1007/s11095-017-2233-0},
  pages     = {2270 -- 2286},
  year      = {2017},
  abstract  = {Comparison of the dissociation kinetics of rapid-acting insulins lispro, aspart, glulisine and human insulin under physiologically relevant conditions. Dissociation kinetics after dilution were monitored directly in terms of the average molecular mass using combined static and dynamic light scattering. Changes in tertiary structure were detected by near-UV circular dichroism. Glulisine forms compact hexamers in formulation even in the absence of Zn2+. Upon severe dilution, these rapidly dissociate into monomers in less than 10 s. In contrast, in formulations of lispro and aspart, the presence of Zn2+ and phenolic compounds is essential for formation of compact R6 hexamers. These slowly dissociate in times ranging from seconds to one hour depending on the concentration of phenolic additives. The disadvantage of the long dissociation times of lispro and aspart can be diminished by a rapid depletion of the concentration of phenolic additives independent of the insulin dilution. This is especially important in conditions similar to those after subcutaneous injection, where only minor dilution of the insulins occurs. Knowledge of the diverging dissociation mechanisms of lispro and aspart compared to glulisine will be helpful for optimizing formulation conditions of rapid-acting insulins.},
  language  = {en}
}
@article{ModlerFabianSokolowskietal.2004,
  author    = {Modler, Andreas Johannes and Fabian, H. and Sokolowski, F. and Lutsch, G. and Gast, Klaus and Damaschun, Gregor},
  title     = {Polymerization of proteins into amyloid protofibrils shares common critical oligomeric states but differs in the mechanisms of their formation},
  year      = {2004},
  abstract  = {Amyloid protofibril formation of phosphoglycerate kinase (PGK) and Syrian hamster prion protein (SHaPrP(90- 232)) were investigated by static and dynamic light scattering, size exclusion chromatography and electron microscopy. Changes in secondary structure were monitored by Fourier transform infrared spectroscopy and by circular dichroism. Protofibril formation of the two proteins is found to be a two-stage process. At the beginning, an ensemble of critical oligomers is built lip. These critical oligomeric states possess a predominant beta-sheet structure and do not interact considerably with monomers. Initial oligomerization and transition to beta-sheet structure are coupled events differing in their details for both proteins. Intermediate oligomeric states (dimers, trimers, etc.) are populated in case of PGK, whereas SHaPrP(90-232) behaves according to oil apparent two-state reaction between monomers and octamers rich in beta- structure with a reaction order varying between 2 and 4. All oligomers coalesce to PGK protofibrils in the second stage, while SHaPrP(90-232) protofibrils are only formed by a subpopulation. The rates of both growth stages can be tuned in case of PGK by different salts preserving the underlying generalized diffusion-collision mechanism. The different kinetics of the early misfolding and oligomerization events of the two proteins argue against a common mechanism of protofibril formation. A classification scheme for misassembly, mechanisms of proteins based on energy landscapes is presented. It includes scenarios of downhill polymerization to which protofibril formation of PGK and SHaPrP(90-232) belong},
  language  = {en}
}
@article{HofmannSorannoBorgiaetal.2012,
  author    = {Hofmann, Hagen and Soranno, Andrea and Borgia, Alessandro and Gast, Klaus and Nettels, Daniel and Schuler, Benjamin},
  title     = {Polymer scaling laws of unfolded and intrinsically disordered proteins quantified with single-molecule spectroscopy},
  series = {Proceedings of the National Academy of Sciences of the United States of America},
  volume    = {109},
  journal   = {Proceedings of the National Academy of Sciences of the United States of America},
  number    = {40},
  publisher = {National Acad. of Sciences},
  address   = {Washington},
  issn      = {0027-8424},
  doi       = {10.1073/pnas.1207719109},
  pages     = {16155 -- 16160},
  year      = {2012},
  abstract  = {The dimensions of unfolded and intrinsically disordered proteins are highly dependent on their amino acid composition and solution conditions, especially salt and denaturant concentration. However, the quantitative implications of this behavior have remained unclear, largely because the effective theta-state, the central reference point for the underlying polymer collapse transition, has eluded experimental determination. Here, we used single-molecule fluorescence spectroscopy and two-focus correlation spectroscopy to determine the theta points for six different proteins. While the scaling exponents of all proteins converge to 0.62 +/- 0.03 at high denaturant concentrations, as expected for a polymer in good solvent, the scaling regime in water strongly depends on sequence composition. The resulting average scaling exponent of 0.46 +/- 0.05 for the four foldable protein sequences in our study suggests that the aqueous cellular milieu is close to effective theta conditions for unfolded proteins. In contrast, two intrinsically disordered proteins do not reach the T-point under any of our solvent conditions, which may reflect the optimization of their expanded state for the interactions with cellular partners. Sequence analyses based on our results imply that foldable sequences with more compact unfolded states are a more recent result of protein evolution.},
  language  = {en}
}
@article{BlasigWinklerLassowskietal.2006,
  author    = {Blasig, Ingolf E. and Winkler, Lars and Lassowski, Birgit and M{\"u}ller, Sandra L. and Zuleger, Nikolaj and Krause, Eberhard and Krause, Gerd and Gast, Klaus and Kolbe, Michael and Piontek, J{\"o}rg},
  title     = {On the self-association potential of transmembrane tight junction proteins},
  issn      = {1420-682X},
  doi       = {10.1007/s00018-005-5472-x},
  year      = {2006},
  abstract  = {Tight junctions seal intercellular clefts via membrane-related strands, hence, maintaining important organ functions. We investigated the self-association of strand-forming transmembrane tight junction proteins. The regulatory tight junction protein occludin was differently tagged and cotransfected in eucaryotic cells. These occludins colocalized within the plasma membrane of the same cell, coprecipitated and exhibited fluorescence resonance energy transfer. Differently tagged strand-forming claudin-5 also colocalized in the plasma membrane of the same cell and showed fluorescence resonance energy transfer. This demonstrates self-association in intact cells both of occludin and claudin-5 in one plasma membrane. In search of dimerizing regions of occludin, dimerization of its cytosolic C-terminal coiled-coil domain was identified. In claudin-5, the second extracellular loop was detected as a dimer. Since the transmembrane junctional adhesion molecule also is known to dimerize, the assumption that homodimerization of transmembrane tight junction proteins may serve as a common structural feature in tight junction assembly is supported},
  language  = {en}
}
@article{KellerSauerStraussetal.2005,
  author    = {Keller, S. and Sauer, I. and Strauss, H. and Gast, Klaus and Dathe, M. and Bienert, Michael C.},
  title     = {Membrane-mimetic nanocarriers formed by a dipalmitoylated cell-penetrating peptide},
  year      = {2005},
  language  = {en}
}
@article{FabianGastLaueetal.2013,
  author    = {Fabian, Heinz and Gast, Klaus and Laue, Michael and Jetzschmann, Katharina J. and Naumann, Dieter and Ziegler, Andreas and Uchanska-Ziegler, Barbara},
  title     = {IR spectroscopic analyses of amyloid fibril formation of beta(2)-microglobulin using a simplified procedure for its in vitro generation at neutral pH},
  series = {Biophysical chemistry : an international journal devoted to the physical chemistry of biological phenomena},
  volume    = {179},
  journal   = {Biophysical chemistry : an international journal devoted to the physical chemistry of biological phenomena},
  number    = {5},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0301-4622},
  doi       = {10.1016/j.bpc.2013.05.001},
  pages     = {35 -- 46},
  year      = {2013},
  abstract  = {beta(2)-microglobulin (beta(2)m) is known to be the major component of fibrillar deposits in the joints of patients suffering from dialysis-related amyloidosis. We have developed a simplified procedure to convert monomeric recombinant beta(2)m into amyloid fibrils at physiological pH by a combination of stirring and heating, enabling us to follow conformational changes associated with the assembly by infrared spectroscopy and electron microscopy. Our studies reveal that fibrillogenesis begins with the formation of relatively large aggregates, with secondary structure not significantly altered by the stirring-induced association. In contrast, the conversion of the amorphous aggregates into amyloid fibrils is associated with a profound re-organization at the level of the secondary and tertiary structures, leading to non-native like parallel arrangements of the beta-strands in the fully formed amyloid structure of beta(2)m. This study highlights the power of an approach to investigate the formation of beta(2)m fibrils by a combination of biophysical techniques including IR spectroscopy.},
  language  = {en}
}
@article{PiontekWinklerBaletal.2004,
  author    = {Piontek, J. and Winkler, Lars and Bal, M. S. and Lassowski, Birgit and Mueller, Sandra L. and Gast, Klaus and Blasig, Ingolf E.},
  title     = {Investigating of homophilic interactions of the tight junction proteins occludin and claudin-5},
  year      = {2004},
  language  = {en}
}
@article{ReschkeSigfridssonKaufmannetal.2013,
  author    = {Reschke, Stefan and Sigfridsson, Kajsa G. V. and Kaufmann, Paul and Leidel, Nils and Horn, Sebastian and Gast, Klaus and Schulzke, Carola and Haumann, Michael and Leimk{\"u}hler, Silke},
  title     = {Identification of a bis-molybdopterin intermediate in molybdenum cofactor biosynthesis in escherichia coli},
  series = {The journal of biological chemistry},
  volume    = {288},
  journal   = {The journal of biological chemistry},
  number    = {41},
  publisher = {American Society for Biochemistry and Molecular Biology},
  address   = {Bethesda},
  issn      = {0021-9258},
  doi       = {10.1074/jbc.M113.497453},
  pages     = {29736 -- 29745},
  year      = {2013},
  abstract  = {The molybdenum cofactor is an important cofactor, and its biosynthesis is essential for many organisms, including humans. Its basic form comprises a single molybdopterin (MPT) unit, which binds a molybdenum ion bearing three oxygen ligands via a dithiolene function, thus forming Mo-MPT. In bacteria, this form is modified to form the bis-MPT guanine dinucleotide cofactor with two MPT units coordinated at one molybdenum atom, which additionally contains GMPs bound to the terminal phosphate group of the MPTs (bis-MGD). The MobA protein catalyzes the nucleotide addition to MPT, but the mechanism of the biosynthesis of the bis-MGD cofactor has remained enigmatic. We have established an in vitro system for studying bis-MGD assembly using purified compounds. Quantification of the MPT/molybdenum and molybdenum/phosphorus ratios, time-dependent assays for MPT and MGD detection, and determination of the numbers and lengths of Mo-S and Mo-O bonds by X-ray absorption spectroscopy enabled identification of a novel bis-Mo-MPT intermediate on MobA prior to nucleotide attachment. The addition of Mg-GTP to MobA loaded with bis-Mo-MPT resulted in formation and release of the final bis-MGD product. This cofactor was fully functional and reconstituted the catalytic activity of apo-TMAO reductase (TorA). We propose a reaction sequence for bis-MGD formation, which involves 1) the formation of bis-Mo-MPT, 2) the addition of two GMP units to form bis-MGD on MobA, and 3) the release and transfer of the mature cofactor to the target protein TorA, in a reaction that is supported by the specific chaperone TorD, resulting in an active molybdoenzyme.},
  language  = {en}
}