Conformational changes in subdomain I of actin induced by proteolytic cleavage within the DNase I‐binding loop: energy transfer from tryptophan to AEDANS

FEBS Letters

Antropova, Olga¹  Khaitlina, Sofia¹  Kuznetsova, Irina¹  Turoverov, Konstantin¹ 

[1] Institute of Cytology, Russian Academy of Sciences, Tikhoretsky av. 4, 194064 St. Petersburg, Russia

关键词: Actin;    Actin proteolysis;    Tryptophan fluorescence;    Energy transfer;    IAEDANS;    N-iodoacetyl-N-(5-sulfo-1-naphthyl)ethylenediamine;    PMSF;    phenylmethylsulfonylfluoride;    SDS-PAGE;    sodium dodecyl sulfate-polyacrylamide gel electrophoresis;   

DOI  :  10.1016/0014-5793(96)00238-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Alteration of the actin polypeptide chain within the DNase I-binding loop by cleavage with E. coli A2 protease or subtilisin was shown to increase the efficiency of energy transfer from tryptophan residues to AEDANS attached to Cys-374. Analysis of structural and fluorescence data suggested that only two of four actin tryptophan residues, namely, Trp-340 and/or Trp-356, can be energy transfer donors. It was also found that labelling with AEDANS induces perturbations in the environment of the tryptophan residues, these perturbations being smaller in the cleaved actin. These changes are consistent with a shift of the C-terminal segment of actin monomer upon cleavage and confirm the existence of high conformational coupling between subdomains 1 and 2 of actin monomer. We also suggest that tryptophan residues 340 and/or 356 are located in the focus of this coupling.

【 授权许可】

Unknown