Open AccessCharacterization of a cloned subtilisin‐like serine proteinase from a psychrotrophic Vibrio species
Author(s) -
Arnórsdóttir Jóhanna,
Smáradóttir Rúna B.,
Magnússon Ólafur Th.,
Thorbjarnardóttir Sigrídur H.,
Eggertsson Gudmundur,
Kristjánsson Magnús M.
Publication year - 2002
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1033.2002.03259.x
Subject(s) - thermus aquaticus , subtilisin , thermus , biochemistry , enzyme , amino acid , biology , serine , peptide sequence , proteinase 3 , proteinase k , thermophile , microbiology and biotechnology , chemistry , gene , myeloperoxidase , immunology , inflammation
The gene encoding a subtilisin‐like serine proteinase in the psychrotrophic Vibrio sp. PA44 has been successfully cloned, sequenced and expressed in Escherichia coli . The gene is 1593 basepairs and encodes a precursor protein of 530 amino acid residues with a calculated molecular mass of 55.7 kDa. The enzyme is isolated, however, as an active 40.6‐kDa proteinase, without a 139 amino acid residue N‐terminal prosequence. Under mild conditions the enzyme undergoes a further autocatalytic cleavage to give a 29.7‐kDa proteinase that retains full enzymatic activity. The deduced amino acid sequence of the enzyme has high homology to proteinases of the proteinase K family of subtilisin‐like proteinases. With respect to the enzyme characteristics compared in this study the properties of the wild‐type and recombinant proteinases are the same. Sequence analysis revealed that especially with respect to the thermophilic homologues, aqualysin I from Thermus aquaticus and a proteinase from Thermus strain Rt41A, the cold‐adapted Vibrio ‐proteinase has a higher content of polar/uncharged amino acids, as well as aspartate residues. The thermophilic enzymes had a higher content of arginines, and relatively higher number of hydrophobic amino acids and a higher aliphatic index. These factors may contribute to the adaptation of these proteinases to different temperature conditions.