Human mesotrypsin defies natural trypsin inhibitors: from passive resistance to active destruction.
More than twenty years ago Rinderknecht et al. identified a minor trypsin isoform resistant to natural trypsin inhibitors in the human pancreatic juice. At the same time, Estell and Laskowski found that an inhibitor-resistant trypsin from the pyloric caeca of the starfish, Dermasterias imbricata rapidly hydrolyzed the reactive-site peptide bonds of trypsin inhibitors. A connection between these two seminal discoveries was made recently, when human mesotrypsin was shown to cleave the reactive-site peptide bond of the Kunitz-type soybean trypsin inhibitor, and degrade the Kazal-type pancreatic secretory trypsin inhibitor. These observations indicate that proteases specialized for the degradation of protease inhibitors are ubiquitous in metazoa, and prompt new investigations into their biological significance. Here we review the history and properties of human mesotrypsin, and discuss its function in the digestive degradation of dietary trypsin inhibitors and possible pathophysiological role in pancreatitis.
Sahin-Tóth
Miklós
M
Department of Molecular and Cell Biology, Boston University, Goldman School of Dental Medicine 715 Albany Street, Evans-4; Boston, MA 02118, USA. miklos@bu.edu
D000818:Animals; D001709:Biotechnology; D014644:Genetic Variation; D006801:Humans; D010179:Pancreas / Q000201:enzymology*; D010195:Pancreatitis / Q000503:physiopathology*; D010455:Peptides / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D013215:Starfish / Q000201:enzymology; D013329:Structure-Activity Relationship; D014357:Trypsin / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D014359:Trypsin Inhibitor, Kazal Pancreatic / Q000378:metabolism; D014361:Trypsin Inhibitors / Q000378:metabolism*
C053865:Kunitz-type protease inhibitor, plant; D010455:Peptides; D010940:Plant Proteins; D014361:Trypsin Inhibitors; D014359:Trypsin Inhibitor, Kazal Pancreatic; C040749:PRSS3 protein, human; D014357:Trypsin