Engineering of the hydrophobic core of an alpha-helical coiled coil

Citation
T. Kiyokawa et al., Engineering of the hydrophobic core of an alpha-helical coiled coil, BIOPOLYMERS, 55(5), 2000, pp. 407-414
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
BIOPOLYMERS
ISSN journal
0006-3525 → ACNP
Volume
55
Issue
5
Year of publication
2000
Pages
407 - 414
Database
ISI
SICI code
0006-3525(2000)55:5<407:EOTHCO>2.0.ZU;2-U
Abstract
The amino acid sequence that forms the alpha -helical coiled coil structure has a representative heptad repeat denoted by defgabc, according to their positions. Although the a and d positions are usually occupied by hydrophob ic residues, hydrophilic residues at these positions sometime play importan t roles in natural proteins. We have manipulated a few amino acids at the a and d positions of a de novo designed trimeric coiled coil to confer new f unctions to the peptides. The IZ peptide, which has four heptad repeats and forms a parallel triple-stranded coiled coil, has Ile at all of the a and d positions. We show three examples: (1) the substitution of one Ile at eit her the a or d position with Glu caused the peptide to become pH sensitive; (2) the metal ion induced alpha -helical bundles were formed by substituti ons with two His residues at the d and a positions for a medium metal ion, and with one Cys residue at the a position for a soft metal ion; and (3) th e AAB-type heterotrimeric alpha -helical bundle formation was accomplished by a combination of Ala and Trp residues at the a positions of different pe ptide chains. Furthermore, we applied these procedures to prepare an ABC-ty pe heterotrimeric alpha -helical bundle and a metal ion-induced heterotrime ric alpha -helical bundle. (C) 2001 John Wiley & Sons, Inc.