Secondary structure of peptides mimicking the Gly-rich regions of major ampullate spidroin protein 1 and 2

Geoffrey M Gray; Brittany Thiessen; Arjan van der Vaart

doi:10.1016/j.bpc.2022.106783

Secondary structure of peptides mimicking the Gly-rich regions of major ampullate spidroin protein 1 and 2

Biophys Chem. 2022 May:284:106783. doi: 10.1016/j.bpc.2022.106783. Epub 2022 Feb 19.

Authors

Geoffrey M Gray¹, Brittany Thiessen¹, Arjan van der Vaart²

Affiliations

¹ Department of Chemistry, University of South Florida, 4202 E. Fowler Ave. CHE 205, Tampa, FL 33620, USA.
² Department of Chemistry, University of South Florida, 4202 E. Fowler Ave. CHE 205, Tampa, FL 33620, USA. Electronic address: avandervaart@usf.edu.

PMID: 35220089
DOI: 10.1016/j.bpc.2022.106783

Abstract

Spider dragline silk has highly desirable material properties, possessing high extensibility, strength, and biocompatibility. Before it is spun, the constituent proteins are stored in a concentrated dope that is void of fibrils. To investigate the structural properties of the amorphous fiber regions in the dope, computer simulations were performed on model peptides representing the N. clavipes Gly-rich regions. Analysis of the secondary structure found predominantly turns, bends and coils; a small 3₁-helical population decreased with increasing concentration. Interestingly, the population of 3₁-helices saw a large increase in octanol. These results indicate that the unusual 3₁-helical secondary structure of the Gly-rich region of the fiber is a consequence of the spinning process, and that the low dielectric environment of the fiber may assist in favoring this structure.

Keywords: 3(1)-helices; Dope; Secondary structure; Simulation; Spider silk.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Fibroins* / chemistry
Peptides
Protein Structure, Secondary
Silk / chemistry
Silk / metabolism

Substances

Peptides
Silk
Fibroins