Isolation and characterization of two new low-molecular-weight protein proteinase inhibitors from the granule-rich fraction of equine neutrophilic granulocytes.
A new species of protein proteinase inhibitors was detected in the granule-rich fraction of equine neutrophilic granulocytes. Five isoinhibitors were identified with a narrow enzyme specificity towards two microbial proteinases, e.g., proteinase K and subtilisin. Two isoinhibitors were purified and partially characterized. They had an Mr of 11,300 and 7400, respectively, and were resistant to perchloric acid and heat treatment at 100 degrees C for 20 min. The inhibitors retained their activity over a broad range of pH (1-9 and 1-12, respectively). The possible biological function of this species of protein proteinase inhibitors as defensins (= endogenous antibiotics) is tentatively discussed.
Pellegrini
A
A
Department of Veterinary Physiology, University of Zürich, Switzerland.
Hägeli
G
G
von Fellenberg
R
R
D000818:Animals; D002458:Cell Fractionation; D003594:Cytoplasmic Granules / Q000032:analysis*; D004355:Drug Stability; D019286:Endopeptidase K; D006736:Horses; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009504:Neutrophils / Q000032:analysis*; D011480:Protease Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D015842:Serine Proteinase Inhibitors; D013347:Subcellular Fractions / Q000032:analysis; D013381:Subtilisins / Q000037:antagonists & inhibitors
D011480:Protease Inhibitors; D015842:Serine Proteinase Inhibitors; D013381:Subtilisins; D019286:Endopeptidase K