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Four‐helix bundle cavitein reveals middle leucine as linchpin
Author(s) -
Freeman Jon O.,
Wallhorn Diana,
Sherman John C.
Publication year - 2007
Publication title -
peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.20718
Subject(s) - chemistry , helix bundle , bundle , leucine , helix (gastropod) , stereochemistry , biochemistry , amino acid , protein structure , zoology , gastropoda , materials science , composite material , biology
A template‐assembled de novo four‐helix bundle is used to examine the hydrophobic effect within the bundle interior. Leu to Ala variants of the basis sequence GG‐EELLKKLEELLKKG were characterized by GuHCl denaturation, NMR dispersion, and N‐H/D exchange experiments. The results show that the middle leucine (L7) is imperative in maintaining bundle stability. The average leucine was found to contribute 1.8 kcal mol −1 toward stability, whereas the middle leucines contribute 2.7 kcal mol −1 each. Substituting alanine into the middle position (7) constitutes a striking 95% reduction of the overall cavitein stability. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 88: 725–732, 2007. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com