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FTIR spectroscopy of complexes formed between metarhodopsin II and C‐terminal peptides from the G‐protein α‐ and γ‐subunits
Author(s) -
Bartl Franz,
Ritter Eglof,
Hofmann Klaus Peter
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)01544-1
Subject(s) - protonation , chemistry , rhodopsin , fourier transform infrared spectroscopy , amide , peptide , stereochemistry , crystallography , biochemistry , organic chemistry , ion , physics , quantum mechanics , retinal
Metarhodopsin II (MII) provides the active conformation of rhodopsin for interaction with the G‐protein, Gt. Fourier transform infrared spectra from samples prepared by centrifugation reflect the pH dependent equilibrium between MII and inactive metarhodopsin I. C‐terminal synthetic peptides (Gtα(340–350) and Gtγ(60–71)farnesyl) stabilize MII. We find that both peptides cause similar spectral changes not seen with control peptides (Gtα (K341R, L349A) and non‐farnesylated Gtγ). The spectra reflect all the protonation dependent bands normally observed when MII is formed at acidic pH. Beside the protonation dependent bands, additional features, similar with both peptides, appear in the amide I and II regions.