@article{MillerSchulerSeckler1998, author = {Miller, Stefan and Schuler, Benjamin and Seckler, Robert}, title = {A reversibly unfolding fragment of P22 tailspike protein with native structure : the isolated beta-helix domain}, year = {1998}, language = {en} } @misc{BestZhengBorgiaetal.2018, author = {Best, Robert B. and Zheng, Wenwei and Borgia, Alessandro and Buholzer, Karin and Borgia, Madeleine B. and Hofmann, Hagen and Soranno, Andrea and Nettels, Daniel and Gast, Klaus and Grishaev, Alexander and Schuler, Benjamin}, title = {Comment on "Innovative scattering analysis shows that hydrophobic disordered proteins are expanded in water"}, series = {Science}, volume = {361}, journal = {Science}, number = {6405}, publisher = {American Assoc. for the Advancement of Science}, address = {Washington}, issn = {0036-8075}, doi = {10.1126/science.aar7101}, pages = {2}, year = {2018}, abstract = {Riback et al. (Reports, 13 October 2017, p. 238) used small-angle x-ray scattering (SAXS) experiments to infer a degree of compaction for unfolded proteins in water versus chemical denaturant that is highly consistent with the results from Forster resonance energy transfer (FRET) experiments. There is thus no "contradiction" between the two methods, nor evidence to support their claim that commonly used FRET fluorophores cause protein compaction.}, language = {en} } @article{BorgiaZhengBuholzeretal.2016, author = {Borgia, Alessandro and Zheng, Wenwei and Buholzer, Karin and Borgia, Madeleine B. and Sch{\"u}ler, Anja and Hofmann, Hagen and Soranno, Andrea and Nettels, Daniel and Gast, Klaus and Grishaev, Alexander and Best, Robert B. and Schuler, Benjamin}, title = {Consistent View of Polypeptide Chain Expansion in Chemical Denaturants from Multiple Experimental Methods}, series = {Journal of the American Chemical Society}, volume = {138}, journal = {Journal of the American Chemical Society}, publisher = {American Chemical Society}, address = {Washington}, issn = {0002-7863}, doi = {10.1021/jacs.6b05917}, pages = {11714 -- 11726}, year = {2016}, abstract = {There has been a long-standing controversy regarding the effect of chemical denaturants on the dimensions of unfolded and intrinsically disordered proteins: A wide range of experimental techniques suggest that polypeptide chains expand with increasing denaturant concentration, but several studies using small-angle X-ray scattering (SAXS) have reported no: such increase of the radius of gyration (R-g). This inconsistency challenges our current understanding of the mechanism of chemical denaturants, which are widely employed to investigate protein folding and stability. Here, we use a combination Of single-molecule Forster resonance energy transfer (FRET), SAXS, dynamic light scattering (DLS), and two-focus fluorescence correlation spectroscopy (2f-FCS) to characterize the denaturant dependence of the unfolded state of the spectrin domain R17 and the intrinsically disordered protein ACTR in two different denaturants. Standard analysis of the primary data clearly indicates an expansion of the unfolded state with increasing denaturant concentration irrespective of the protein, denaturant, or experimental method used. This is the first case in which SAXS and FRET have yielded even qualitatively consistent results regarding expansion in denaturant when applied to the same proteins. To more directly illustrate this self-consistency, we used both SAXS and FRET data in a Bayesian procedure to refine structural ensembles representative of the observed unfolded state. This analysis demonstrates that both of these experimental probes are compatible with a common ensemble of protein configurations for each denaturant concentration. Furthermore, the resulting ensembles reproduce the trend of increasing hydrodynamic radius, with denaturant concentration obtained by 2f-FCS,and DLS. We were thus able to reconcile the results from all four experimental techniques quantitatively, to obtain a comprehensive structural picture of denaturant;induced unfolded state expansion, and to identify the Most likely sources of earlier discrepancies.}, language = {en} } @article{SchulerRachelSeckler1999, author = {Schuler, Benjamin and Rachel, Reinhard and Seckler, Robert}, title = {Formation of fibrous aggregates from a non-native intermediate : the isolated P22 tailspike -helix domain}, year = {1999}, language = {en} } @article{BuscagliaSchulerLapidusetal.2003, author = {Buscaglia, Marco and Schuler, Benjamin and Lapidus, Lisa J. and Eaton, Wiliam A. and Hofrichter, James}, title = {Kinetics of intramolecular contact formation in a denatured protein}, issn = {0022-2836}, year = {2003}, abstract = {Quenching of the triplet state of tryptophan by cysteine has provided a new tool for measuring the rate of forming a specific intramolecular contact in disordered polypeptides. Here, we use this technique to investigate contact formation in the denatured state of CspTm, a small cold-shock protein from Thermotoga maritima, engineered to contain a single tryptophan residue (W29) and a single cysteine residue at the C terminus (C67). At all concentrations of denaturant, the decay rate of the W29 triplet of the unfolded protein is more than tenfold faster than the rate observed for the native protein (not, vert, similar104 s;1). Experiments on the unfolded protein without the added C- terminal cysteine residue show that this faster rate results entirely from contact quenching by C67. The quenching rate in the unfolded state by C67 increases at concentrations of denaturant that favor folding, indicating a compaction of the unfolded protein as observed previously in single-molecule Foerster resonance energy transfer (FRET) experiments.}, language = {en} } @article{HoffmannKaneNettelsetal.2007, author = {Hoffmann, Armin S. and Kane, Avinash S. and Nettels, Daniel and Hertzog, David E. and Baumg{\"a}rtel, Peter and Lengefeld, Jan and Reichardt, Gerd and Horsley, David A. and Seckler, Robert and Bakajin, Olgica and Schuler, Benjamin}, title = {Mapping protein collapse with single molecule fluorescence and kinetic synchrotron radiation circular dichroism spectroscopy}, issn = {0027-8424}, year = {2007}, language = {en} } @article{KaneHoffmannBaumgaerteletal.2008, author = {Kane, Avinash S. and Hoffmann, Armin S. and Baumg{\"a}rtel, Peter and Seckler, Robert and Reichardt, Gerd and Horsley, David A. and Schuler, Benjamin and Bakajin, Olgica}, title = {Microfluidic mixers for the investigation of rapid protein folding kinetics using synchrotron radiation circular dichroism spectroscopy}, issn = {0003-2700}, year = {2008}, abstract = {We have developed a microfluidic mixer optimized for rapid measurements of protein folding kinetics using synchrotron radiation circular dichroism (SRCD) spectroscopy. The combination of fabrication in fused silica and synchrotron radiation allows measurements at wavelengths below 220 nm, the typical limit of commercial instrumentation. At these wavelengths, the discrimination between the different types of protein secondary structure increases sharply. The device was optimized for rapid mixing at moderate sample consumption by employing a serpentine channel design, resulting in a dead time of less than 200 ;s. Here, we discuss the design and fabrication of the mixer and quantify the mixing efficiency using wide-field and confocal epi-fluorescence microscopy. We demonstrate the performance of the device in SRCD measurements of the folding kinetics of cytochrome c, a small, fast-folding protein. Our results show that the combination of SRCD with microfluidic mixing opens new possibilities for investigating rapid conformational changes in biological macromolecules that have previously been inaccessible.}, language = {en} } @article{SchulerSeckler1998, author = {Schuler, Benjamin and Seckler, Robert}, title = {P22 tailspike folding mutants revisited : effects on thermodynamic stability of the isolated beta-helix domain}, year = {1998}, language = {en} } @article{GoetzSuopankiSchuleretal.2005, author = {Goetz, C. and Suopanki, J. and Schuler, Benjamin and Wanker, E. and Herrmann, Andreas}, title = {Perturbation of brain lipid membrane by soluble Huntingtin depends on its polyproline tract}, issn = {0006-3495}, year = {2005}, language = {en} } @article{MillerSchulerSeckler1998, author = {Miller, Stefan and Schuler, Benjamin and Seckler, Robert}, title = {Phages P22 tailspike protein: Removal of head-binding domain unmasks efects of folding mutations on native- state thermal stability}, year = {1998}, language = {en} }