Amino acid sequence determination and biological activity of therin, a naturally occuring specific trypsin inhibitor from the leech Theromyzon tessulatum.
We purified a trypsin inhibitor, designated therin, from the rhynchobdellid leech Theromyzon tessulatum. Therin was purified to apparent homogeneity by gel-permeation and anion-exchange chromatography followed by reverse-phase HPLC. By a combination of reduction and S-beta-pyridylethylation, Edman degradation and electrospray mass spectrometry measurement, the complete sequence of therin (48 amino acid residues; m/z, 5376.35 +/- 0.22 Da) was determined. Therin exhibits an approximately 30% sequence similarity with peptides of the antistasin-type inhibitors family, i.e. the first and second domains of antistasin, hirustasin, ghilanthen and guamerins (I, II). Therin is a tight-binding inhibitor of trypsin (Ki, 45 +/- 12 pM) and has no action towards elastase or cathepsin G. Furthermore, therin (10(-6) M) in conjunction with theromin, a Theromyzon thrombin inhibitor (10(-6) M) significantly diminish the level of human leucocytes activation induced by lipopolysaccharide (10 microg) in a manner similar to that of aprotinin. These data suggest a leech trypsin inhibitor with possible biomedical significance.
Chopin
V
V
Centre de Biologie Cellulaire, Laboratoire d'Endocrinologie des Annélides, Université des Sciences et Technologie de Lille, Villeneuve d'Ascq, France.
Matias
I
I
Stefano
G B
GB
Salzet
M
M
D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D006801:Humans; D007865:Leeches / Q000737:chemistry*; D007962:Leukocytes / Q000187:drug effects; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D014361:Trypsin Inhibitors / Q000737:chemistry* / Q000494:pharmacology
D000276:Adjuvants, Immunologic; D009842:Oligopeptides; D014361:Trypsin Inhibitors; C113612:therin