Reassessment of the putative chaperone function of prolyl‐cis/trans‐isomerases

FEBS Letters

Kern, Dorothee²  Schmid, Franz X.¹  Kern, Gunther²  Fischer, Gunter² 

[1] Laboratorium für Biochemie, Universität Bayreuth, D-95440 Bayreuth, Germany;Max-Planck-Arbeitsgruppe Enzymologie der Peptidbindung, Weinbergweg 16A, D-06120 Halle/Saale, Germany

关键词: Peptidyl-prolyl-cis/trans-isomerase;    Carbonic anhydrase;    Chaperone;    Folding;   

DOI  :  10.1016/0014-5793(94)00591-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The folding of proteins can be assisted by two unrelated groups of helper molecules. Chaperones suppress non-productive side reactions by stoichiometric binding to folding intermediates, and folding enzymes catalyze slow rate-limiting steps of folding. We reinvestigated, whether peptidyl-propyl-cis/trans-isomerases of the cyclophilin type act simultaneously as chaperones and as folding catalysts in the reactivation of human carbonic anhydrase II, as reported recently [Freskgård, P.-O et al. (1992) Science 258, 466–468; Rinfret, A. et al. (1994) Biochemistry 33, 1668–1673]. No increase in the yield of carbonic anhydrase-II could be detected in the presence of three different propyl isomerases, when reactivation was followed by a sensitive assay for an extended time of 4 h. We conclude that the role of propyl isomerases in the refolding of carbonic anhydrase can be explained solely by their isomerase activity. There is no need to invoke simultaneous functions as chaperones for these folding catalysts.

【 授权许可】

Unknown