Functional roles of C-terminal extension (CTE) of salt-dependent peptidase activity of the Natrialba magadii extracellular protease (NEP).
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES(2018)
摘要
Nep (Natrialba magadii extracellular protease) is a halolysin-like peptidase secreted by the haloalkaliphilic archaeon Natrialba magadii. Many extracellular proteases have been characterized from archaea to bacteria as adapted to hypersaline environments retaining function and stability until 4.0 M NaCI. As observed in other secreted halolysins, this stability can be related to the presence of a C-terminal extension (CTE) sequence. In the present work, we compared the biochemical properties of recombinant Nep protease with the truncated form at the 134 amino acids CTE (Nep Delta KTE), that was more active in 4 M NaCI than the non-truncated wild type enzyme. Comparable to the wild type, Nep Delta CTE protease is irreversibly inactivated at low salt solutions. The substrate specificity of the truncated Nep Delta CTE was similar to that of wild type form as demonstrated by a combinatorial library of FRET substrates. The enzyme stability, the effect of different salts and the thermodynamics assays using different lengths of substrates demonstrated similarities between the two forms. Altogether, these data provide further information on the stability and structural determinants of halolysins under different salinities, especially concerning the enzymatic behavior. (C) 2018 Elsevier B.V. All rights reserved.
更多查看译文
关键词
Serine protease,Natrialba magadii,Haloalkaliphilic protease
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络