Synthesis, conformation, and activity of human insulin-like Peptide 5 (INSL5)

Hossain, Mohammed Akhter, Bathgate, Ross A. D., Kong, Chze K., Shabanpoor, Fazel, Suode Zhang, Haugaard-Jönsson, Linda M., Rosengren, K. Johan, Tregear, Geoffrey W. and Wade, John D. (2008) Synthesis, conformation, and activity of human insulin-like Peptide 5 (INSL5). ChemBioChem, 9 11: 1816-1822. doi:10.1002/cbic.200800113

Author Hossain, Mohammed Akhter
Bathgate, Ross A. D.
Kong, Chze K.
Shabanpoor, Fazel
Suode Zhang
Haugaard-Jönsson, Linda M.
Rosengren, K. Johan
Tregear, Geoffrey W.
Wade, John D.
Title Synthesis, conformation, and activity of human insulin-like Peptide 5 (INSL5)
Journal name ChemBioChem   Check publisher's open access policy
ISSN 1439-4227
Publication date 2008-07-21
Year available 2008
Sub-type Article (original research)
DOI 10.1002/cbic.200800113
Volume 9
Issue 11
Start page 1816
End page 1822
Total pages 7
Place of publication Weinheim, Germany
Publisher Wiley-VCH Verlag
Language eng
Subject 06 Biological Sciences
0601 Biochemistry and Cell Biology
0304 Medicinal and Biomolecular Chemistry
Abstract Insulin-like peptide 5 (INSL5) was first identified through searches of the expressed sequence tags (EST) databases. Primary sequence analysis showed it to be a prepropeptide that was predicted to be processed in vivo to yield a two-chain sequence (A and B) that contained the insulin-like disulfide cross-links. The high affinity interaction between INSL5 and the receptor RXFP4 (GPCR142) coupled with their apparent coevolution and partially overlapping tissue expression patterns strongly suggest that INSL5 is an endogenous ligand for RXFP4. Given that the primary function of the INSL5–RXFP4 pair remains unknown, an effective means of producing sufficient quantities of this peptide and its analogues is needed to systematically investigate its structural and biological properties. A combination of solid-phase peptide synthesis methods together with regioselective disulfide bond formation were used to obtain INSL5. Both chains were unusually resistant to standard synthesis protocols and required highly optimized conditions for their acquisition. In particular, the use of a strong tertiary amidine, DBU, as Na-deprotection base was required for the successful assembly of the B chain; this highlights the need to consider incomplete deprotection rather than acylation as a cause of failed synthesis. Following sequential disulfide bond formation and chain combination, the resulting synthetic INSL5, which was obtained in good overall yield, was shown to possess a similar secondary structure to human relaxin-3 (H3 relaxin). The peptide was able to inhibit cAMP activity in SK-N-MC cells that expressed the human RXFP4 receptor with a similar activity to H3 relaxin. In contrast, it had no activity on the human RXFP3 receptor. Synthetic INSL5 demonstrates equivalent activity to the recombinant-derived peptide, and will be an important tool for the determination of its biological function.
Keyword Circular dichroism
Insulin-like peptides
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
Institute for Molecular Bioscience - Publications
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Created: Tue, 22 Dec 2009, 20:24:51 EST by Macushla Boyle on behalf of Institute for Molecular Bioscience