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New members of the brachyurins family in lobster include a trypsin‐like enzyme with amino acid substitutions in the substrate‐binding pocket
Author(s) -
Perera Erick,
Pons Tirso,
Hernandez Damir,
Moyano Francisco J.,
MartínezRodríguez Gonzalo,
Mancera Juan M.
Publication year - 2010
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2010.07751.x
Subject(s) - trypsin , biochemistry , serine , chymotrypsin , enzyme , proteases , biology , amino acid , protease , gene family , gene , gene expression
Crustacean serine proteases (Brachyurins, EC 3.4.21.32) exhibit a wide variety of primary specificities and no member of this family has been reported for spiny lobsters. The aim of this work was to study the diversity of trypsins in the digestive gland of Panulirus argus . Several trypsin‐like proteases were cloned and the results suggest that at least three gene families encode trypsins in the lobster. Three‐dimensional comparative models of each trypsin anticipated differences in the interaction of these enzymes with proteinaceous substrates and inhibitors. Most of the studied enzymes were typical trypsins, but one could not be allocated to any of the brachyurins groups due to amino acid substitutions found in the vicinity of the active site. Among other changes in this form of the enzyme, conserved Gly216 and Gly226 (chymotrypsin numbering) are substituted by Leu and Pro, respectively, while retaining all other key residues for trypsin specificity. These substitutions may impair the access of bulky residues to the S1 site while they make the pocket more hydrophobic. The physiological role of this form of the enzyme could be relevant as it was found to be highly expressed in lobster. Further studies on the specificity and structure of this variant must be performed to locate it within the brachyurins family. It is suggested that specificity within this family of enzymes is broader than is currently believed.