Binding of Streptomyces pepsin inhibitor (acetyl-pepstatin) with chymosin (Rennin).
Chymosin (Rennin) was effectively purified using an AH-Sepharose 4B column. Binding of Streptomyces pepsin inhibitor (acetul-pepstatin) with chymosin was studied spectroscopically. The binding caused ultraviolet difference and CD spectral changes suggesting microenvironmental changes around tryptophan and/or tyrosine residue(s) in chymosin. The fluorescence intensity of a hydrophobic probe, 2-p-toluidinylnaphthalene-6-sulfonate, increased in the presence of chymosin and was further amplified when Streptomyces pepsin inhibitor was added to the chymosin-2-p-toluidinylnaphthalene-6-sulfonate solution. The binding and dissociation-rate constants between chymosin and the inhibitor were determined using 2-p-toluidinylhnaphthalene-6-sulfonate as a probe. The binding constant was determined from the binding and dissociation-rate constants, to be 3.1 . 10(7) M-1 at 25 degrees C, pH 5.5.
D012085:Chymosin / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D009282:Naphthalenesulfonates / Q000494:pharmacology*; D009842:Oligopeptides / Q000378:metabolism*; D010434:Pepsin A / Q000037:antagonists & inhibitors*; D010436:Pepstatins / Q000378:metabolism*; D013302:Streptomyces; D014466:Ultraviolet Rays
D009282:Naphthalenesulfonates; D009842:Oligopeptides; D010436:Pepstatins; C014195:Streptomyces pepsin inhibitor; C009497:2-(4-toluidino)-6-naphthalenesulfonic acid; D010434:Pepsin A; D012085:Chymosin