title: A serine proteinase inhibitor isolated from Tamarindus indica seeds and its effects on the release of human neutrophil elastase.
abstract: Proteinaceous inhibitors with high inhibitory activities against human neutrophil elastase (HNE) were found in seeds of the Tamarind tree (Tamarindus indica). A serine proteinase inhibitor denoted PG50 was purified using ammonium sulphate and acetone precipitation followed by Sephacryl S-300 and Sephadex G-50 gel filtration chromatographies. Inhibitor PG50 showed a Mr of 14.9 K on Sephadex G-50 calibrated column and a Mr of 11.6 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. PG50 had selective activity while cysteine proteinases (papain and bromelain) and serine proteinases (porcine pancreatic elastase and bovine chymotrypsin) were not inhibited, it was strongly effective against serine proteinases such as bovine trypsin and isolated human neutrophil elastase. The IC50 value was determined to be 55.96 microg.mL-1. PG50 showed neither cytotoxic nor haemolytic activity on human blood cells. After pre-incubation of PG50 with cytochalasin B, the exocytosis of elastase was initiated using PAF and fMLP. PG50 exhibited different inhibition on elastase release by PAF, at 44.6% and on release by fMLP, at 28.4%. These results showed that PG50 preferentially affected elastase release by PAF stimuli and this may indicate selective inhibition on PAF receptors.
authors.affiliation: Departamento de Bioquímica, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Campus Universitário, 59072-970, Natal, RN, Brasil.
authors.forename: J M S L L
authors.initials: JM
authors.lastname: Fook
authors.forename: L L P
authors.initials: LL
authors.lastname: Macedo
authors.forename: G E D D
authors.initials: GE
authors.lastname: Moura
authors.forename: F M
authors.initials: FM
authors.lastname: Teixeira
authors.forename: A S
authors.initials: AS
authors.lastname: Oliveira
authors.forename: A F S
authors.initials: AF
authors.lastname: Queiroz
authors.forename: M P
authors.initials: MP
authors.lastname: Sales
mesh_terms: D000180:Acrylic Resins; D001773:Blood Cells / Q000502:physiology; D001963:Bromelains / Q000378:metabolism; D002470:Cell Survival / Q000502:physiology; D002850:Chromatography, Gel; D002918:Chymotrypsin / Q000378:metabolism; D003911:Dextrans; D004591:Electrophoresis, Polyacrylamide Gel; D005434:Flow Cytometry; D006801:Humans; D020128:Inhibitory Concentration 50; D019272:Leukocyte Elastase / Q000037:antagonists & inhibitors*; D010196:Pancreatic Elastase / Q000378:metabolism; D010206:Papain / Q000378:metabolism; D010980:Platelet Membrane Glycoproteins / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D012639:Seeds / Q000737:chemistry*; D015842:Serine Proteinase Inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D029861:Tamarindus / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; D003911:Dextrans; D010980:Platelet Membrane Glycoproteins; D043562:Receptors, G-Protein-Coupled; C037239:Sephacryl Superfine; D015842:Serine Proteinase Inhibitors; C039351:platelet activating factor receptor; D001963:Bromelains; C025614:sephadex; D002918:Chymotrypsin; D010196:Pancreatic Elastase; D019272:Leukocyte Elastase; D010206:Papain