Detection of a very rapid first phase in complex formation of DnaK and peptide substrate

FEBS Letters

Christen, Philipp¹  Baici, Antonio¹  Koller, Michael F.¹  Huber, Michael¹ 

[1] Biochemisches Institut der Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland

关键词: Molecular chaperone;    Hsp70;    DnaK;    Kinetics of Hsp70;    Stopped-flow technique;    Fluorescence-labeled peptide;    a-ala-p5;    acrylodan-labeled peptide ala-p5 (ALLLSAPRR);    a-NR;    acrylodan-labeled peptide NR (NRLLLTG);    Hsc70;    70-kDa heat shock cognate protein;    Hsp70;    70-kDa heat shock protein;   

DOI  :  10.1016/S0014-5793(02)02752-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Complex formation of the Hsp70 chaperone DnaK with the fluorescence-labeled peptide ALLLSAPRR shows a very rapid first phase that has as yet not been observed with other peptides. This first phase is completed within the dead time (1–2 ms) of the stopped-flow instrument and corresponds to two thirds of the total increase in fluorescence. It occurs both in the presence and in the absence of ATP and is followed by a fast, a slow and a very slow step. These binding kinetics that are vastly different from those observed with other peptides might indicate the existence of a second substrate-binding site of DnaK.

【 授权许可】

Unknown