Four residues of propeptide are essential for precursor folding of nattokinase

Yan Jia, Xinhua Cao, Yu Deng, Wei Bao, Changyan Tang, Hanjing Ding, Zhongliang Zheng, and Guolin Zou

Beijing Key Laboratory of Plants Resource Research and Development, School of Science, Beijing Technology and Business University, Beijing 100048, China

Subtilisin propeptide functions as an intramolecular chaperone that guides precursorfolding. Nattokinase, a member of subtilisin family, is synthesized as a precursor consisting of a signal peptide, a propeptide, and a subtilisin domain, and the mechanism of its folding remains to be understood. In this study, the essentialresidues of nattokinasepropeptide which contribute to precursorfolding were determined. Deletion analysis showed that the conserved regions in propeptide were important for precursorfolding. Single-site and multi-site mutagenesis studies confirmed the role of Tyr10, Gly13, Gly34, and Gly35. During stage (i) and (ii) of precursorfolding, Tyr10 and Gly13 would form the part of interface with subtilisin domain. While Gly34 and Gly35 connected with an α-helix that would stabilize the structure of propeptide. The quadruple Ala mutation, Y10A/G13A/G34A/G35A, resulted in a loss of the chaperone function for the propeptide. This work showed the essentialresidues of propeptide for precursorfolding via secondary structure and kinetic parameter analyses.

图例: 纳豆激酶前体肽和subtilisin域之间的相互作用

Acta Biochim Biophys Sin (Shanghai). 2014 Nov;46(11):957-64. doi: 10.1093/abbs/gmu093

全文: http://abbs.oxfordjournals.org/content/46/11/957.full