TY  - JOUR
A1  - Wolff, Martin
A1  - Schüler, Anja
A1  - Gast, Klaus
A1  - Seckler, Robert
A1  - Evers, Andreas
A1  - Pfeiffer-Marek, Stefania
A1  - Kurz, Michael
A1  - Nagel, Norbert
A1  - Haack, Torsten
A1  - Wagner, Michael
A1  - Thalhammer, Anja
T1  - Self-Assembly of Exendin-4-Derived Dual Peptide Agonists is Mediated by Acylation and Correlated to the Length of Conjugated Fatty Acyl Chains
JF  - Molecular pharmaceutics
N2  - 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.
KW  - dual GLP-1/glucagon receptor agonist
KW  - self-assembly
KW  - light scattering
KW  - molecular architecture
KW  - lipidation
KW  - exendin-4
Y1  - 2020
U6  - https://doi.org/10.1021/acs.molpharmaceut.9b01195
SN  - 1543-8384
SN  - 1543-8392
VL  - 17
IS  - 3
SP  - 965
EP  - 978
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Wolff, Martin
A1  - Gast, Klaus
A1  - Evers, Andreas
A1  - Kurz, Michael
A1  - Pfeiffer-Marek, Stefania
A1  - Schüler, Anja
A1  - Seckler, Robert
A1  - Thalhammer, Anja
T1  - A Conserved Hydrophobic Moiety and Helix-Helix Interactions Drive the Self-Assembly of the Incretin Analog Exendin-4
JF  - Biomolecules
N2  - Exendin-4 is a pharmaceutical peptide used in the control of insulin secretion. Structural information on exendin-4 and related peptides especially on the level of quaternary structure is scarce. We present the first published association equilibria of exendin-4 directly measured by static and dynamic light scattering. We show that exendin-4 oligomerization is pH dependent and that these oligomers are of low compactness. We relate our experimental results to a structural hypothesis to describe molecular details of exendin-4 oligomers. Discussion of the validity of this hypothesis is based on NMR, circular dichroism and fluorescence spectroscopy, and light scattering data on exendin-4 and a set of exendin-4 derived peptides. The essential forces driving oligomerization of exendin-4 are helix–helix interactions and interactions of a conserved hydrophobic moiety. Our structural hypothesis suggests that key interactions of exendin-4 monomers in the experimentally supported trimer take place between a defined helical segment and a hydrophobic triangle constituted by the Phe22 residues of the three monomeric subunits. Our data rationalize that Val19 might function as an anchor in the N-terminus of the interacting helix-region and that Trp25 is partially shielded in the oligomer by C-terminal amino acids of the same monomer. Our structural hypothesis suggests that the Trp25 residues do not interact with each other, but with C-terminal Pro residues of their own monomers.
KW  - biophysics
KW  - diabetes
KW  - peptides
KW  - oligomerization
KW  - conformational change
KW  - molecular modeling
KW  - static and dynamic light scattering
KW  - spectroscopy
Y1  - 2021
U6  - https://doi.org/10.3390/biom11091305
SN  - 2218-273X
VL  - 11
IS  - 9
PB  - MDPI
CY  - Basel
ER  - 
TY  - GEN
A1  - Wolff, Martin
A1  - Gast, Klaus
A1  - Evers, Andreas
A1  - Kurz, Michael
A1  - Pfeiffer-Marek, Stefania
A1  - Schüler, Anja
A1  - Seckler, Robert
A1  - Thalhammer, Anja
T1  - A Conserved Hydrophobic Moiety and Helix-Helix Interactions Drive the Self-Assembly of the Incretin Analog Exendin-4
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Exendin-4 is a pharmaceutical peptide used in the control of insulin secretion. Structural information on exendin-4 and related peptides especially on the level of quaternary structure is scarce. We present the first published association equilibria of exendin-4 directly measured by static and dynamic light scattering. We show that exendin-4 oligomerization is pH dependent and that these oligomers are of low compactness. We relate our experimental results to a structural hypothesis to describe molecular details of exendin-4 oligomers. Discussion of the validity of this hypothesis is based on NMR, circular dichroism and fluorescence spectroscopy, and light scattering data on exendin-4 and a set of exendin-4 derived peptides. The essential forces driving oligomerization of exendin-4 are helix–helix interactions and interactions of a conserved hydrophobic moiety. Our structural hypothesis suggests that key interactions of exendin-4 monomers in the experimentally supported trimer take place between a defined helical segment and a hydrophobic triangle constituted by the Phe22 residues of the three monomeric subunits. Our data rationalize that Val19 might function as an anchor in the N-terminus of the interacting helix-region and that Trp25 is partially shielded in the oligomer by C-terminal amino acids of the same monomer. Our structural hypothesis suggests that the Trp25 residues do not interact with each other, but with C-terminal Pro residues of their own monomers.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1161 
KW  - biophysics
KW  - diabetes
KW  - peptides
KW  - oligomerization
KW  - conformational change
KW  - molecular modeling
KW  - static and dynamic light scattering
KW  - spectroscopy
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-522081
SN  - 1866-8372
IS  - 9
ER  - 
TY  - JOUR
A1  - Wolff, Martin
A1  - Schüler, Anja
A1  - Gast, Klaus
A1  - Seckler, Robert
A1  - Evers, Andreas
A1  - Pfeiffer-Marek, Stefania
A1  - Kurz, Michael
A1  - Nagel, Norbert
A1  - Haack, Torsten
A1  - Wagner, Michael
A1  - Thalhammer, Anja
T1  - Self-Assembly of Exendin-4-Derived Dual Peptide Agonists is Mediated by Acylation and Correlated to the Length of Conjugated Fatty Acyl Chains
JF  - Molecular pharmaceutics
N2  - 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.
KW  - dual GLP-1/glucagon receptor agonist
KW  - self-assembly
KW  - light scattering
KW  - molecular architecture
KW  - lipidation
KW  - exendin-4
Y1  - 2020
U6  - https://doi.org/10.1021/acs.molpharmaceut.9b01195
SN  - 1543-8384
VL  - 17
IS  - 3
SP  - 965
EP  - 978
PB  - American Chemical Society
CY  - Washington
ER  -