Truncated Glucagon-like Peptide-1 and Exendin-4 α-Conotoxin pl14a Peptide Chimeras Maintain Potency and α-Helicity and Reveal Interactions Vital for cAMP Signaling in Vitro.

Autor:	Swedberg JE; From the Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072 Queensland, Australia., Schroeder CI; From the Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072 Queensland, Australia., Mitchell JM; From the Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072 Queensland, Australia., Fairlie DP; From the Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072 Queensland, Australia., Edmonds DJ; Worldwide Medicinal Chemistry, Cardiovascular and Metabolic Diseases Research Unit, Pfizer Inc., Cambridge, Massachusetts 02139, and., Griffith DA; Worldwide Medicinal Chemistry, Cardiovascular and Metabolic Diseases Research Unit, Pfizer Inc., Cambridge, Massachusetts 02139, and., Ruggeri RB; Worldwide Medicinal Chemistry, Cardiovascular and Metabolic Diseases Research Unit, Pfizer Inc., Cambridge, Massachusetts 02139, and., Derksen DR; Pharmacokinetics, Dynamics, and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut 06340., Loria PM; Pharmacokinetics, Dynamics, and Metabolism, Worldwide Research and Development, Pfizer Inc., Groton, Connecticut 06340., Price DA; Worldwide Medicinal Chemistry, Cardiovascular and Metabolic Diseases Research Unit, Pfizer Inc., Cambridge, Massachusetts 02139, and., Liras S; Worldwide Medicinal Chemistry, Cardiovascular and Metabolic Diseases Research Unit, Pfizer Inc., Cambridge, Massachusetts 02139, and., Craik DJ; From the Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072 Queensland, Australia, d.craik@imb.uq.edu.au.
Jazyk:	angličtina
Zdroj:	The Journal of biological chemistry [J Biol Chem] 2016 Jul 22; Vol. 291 (30), pp. 15778-87. Date of Electronic Publication: 2016 May 10.
DOI:	10.1074/jbc.M116.724542
Abstrakt:	Glucagon-like peptide-1 (GLP-1) signaling through the glucagon-like peptide 1 receptor (GLP-1R) is a key regulator of normal glucose metabolism, and exogenous GLP-1R agonist therapy is a promising avenue for the treatment of type 2 diabetes mellitus. To date, the development of therapeutic GLP-1R agonists has focused on producing drugs with an extended serum half-life. This has been achieved by engineering synthetic analogs of GLP-1 or the more stable exogenous GLP-1R agonist exendin-4 (Ex-4). These synthetic peptide hormones share the overall structure of GLP-1 and Ex-4, with a C-terminal helical segment and a flexible N-terminal tail. Although numerous studies have investigated the molecular determinants underpinning GLP-1 and Ex-4 binding and signaling through the GLP-1R, these have primarily focused on the length and composition of the N-terminal tail or on how to modulate the helicity of the full-length peptides. Here, we investigate the effect of C-terminal truncation in GLP-1 and Ex-4 on the cAMP pathway. To ensure helical C-terminal regions in the truncated peptides, we produced a series of chimeric peptides combining the N-terminal portion of GLP-1 or Ex-4 and the C-terminal segment of the helix-promoting peptide α-conotoxin pl14a. The helicity and structures of the chimeric peptides were confirmed using circular dichroism and NMR, respectively. We found no direct correlation between the fractional helicity and potency in signaling via the cAMP pathway. Rather, the most important feature for efficient receptor binding and signaling was the C-terminal helical segment (residues 22-27) directing the binding of Phe(22) into a hydrophobic pocket on the GLP-1R. (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu