TAILIEUCHUNG - Báo cáo khoa học: Purification and characterization of pepsins A1 and A2 from the Antarctic rock cod Trematomus bernacchii

The Antarctic notothenioidTrematomus bernacchii(rock cod) lives at a constant mean temperature of) C. Gastric digestion under these con-ditions relies on the proteolytic activity of aspartic proteases such as pep-sin. | ễFEBS Journal Purification and characterization of pepsins A1 and A2 from the Antarctic rock cod Trematomus bernacchii Sébastien Brier1 Giovanna Maria2 Vincenzo Carginale2 Antonio Capasso2 Yan Wu1 Robert M. Taylor1 Nicholas B. Borotto1 Clemente Capasso2 and John R. Engen1 1 Department of Chemistry ChemicalBiology and The Barnett Institute for Chemical BiologicalAnalysis Northeastern University Boston MA USA 2 CNR Institute of Protein Biochemistry Naples Italy Keywords aspartic proteases cold-adapted protein rock cod specificity Correspondence J. R. Engen 341 Mugar Life Sciences Barnett Institute Northeastern University 360 Huntington Avenue Boston MA 02115-5000 USA Fax 1 617 373 2855 Tel 1 617 373 6046 E-mail Received 23 August 2007 revised 2 October 2007 accepted 10 October 2007 doi The Antarctic notothenioid Trematomus bernacchii rock cod lives at a constant mean temperature of - C. Gastric digestion under these conditions relies on the proteolytic activity of aspartic proteases such as pepsin. To understand the molecular mechanisms of Antarctic fish pepsins T. bernacchii pepsins A1 and A2 were cloned overexpressed in Escherichia coli purified and characterized with a number of biochemical and biophysical methods. The properties of these two Antarctic isoenzymes were compared to those of porcine pepsin and found to be unique in a number of ways. Fish pepsins were found to be more temperature sensitive generally less active at lower pH and more sensitive to inhibition by pepstatin than their mesophilic counterparts. The specificity of Antarctic fish pepsins was similar but not identical to that of pig pepsin probably owing to changes in the sequence of fish enzymes near the active site. Gene duplication of Antarctic rock cod pepsins is the likely mechanism for adaptation to the harsh temperature environment in which these enzymes must function. One of the peculiarities characterizing Antarctic noto-thenioids is

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