title: Polypeptide halomethyl ketones bind to serine proteases as analogs of the tetrahedral intermediate. X-ray crystallographic comparison of lysine- and phenylalanine-polypeptide chloromethyl ketone-inhibited subtilisin.
abstract: 1. A detailed study of cytochrome C oxidse activity with Keilin-Hartree particles and purified beef heart enzyme, at low ionic strength and low cytochrome C concentrations, showed biphasic kinetics with apparent Km1 = 5 x 10(-8) M, and apparent Km2 = 0.35 to 1.0 x 10(-6) M. Direct binding studies with purified oxidase, phospholipid-containing as well as phospholipid-depleted, demonstrated two sites of interaction of cytochrome c with the enzyme, with KD2 less than or equal to 10(-7) M, and KD2 = 10(-6) M. 2...
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D005583:Fourier Analysis; D007659:Ketones; D008958:Models, Molecular; D010455:Peptides; D011485:Protein Binding; D011487:Protein Conformation; D013381:Subtilisins / Q000037:antagonists & inhibitors; D014961:X-Ray Diffraction
chemical_list: D007659:Ketones; D010455:Peptides; D013381:Subtilisins