Penicillin is hydrolyzed and thereby rendered inactive by penicillinase (also known as ?-lactamase), an enzyme present in
Question:
Penicillin is hydrolyzed and thereby rendered inactive by penicillinase (also known as ?-lactamase), an enzyme present in some penicillin-resistant bacteria. The mass of this enzyme in Staphylococcus aureus is 29.6 kDa. The amount of penicillin hydrolyzed in 1 minute in a 10 mL solution containing 10 -9 g of purified penicillinase was measured as a function of the concentration of penicillin. Assume that the concentration of penicillin does not change appreciably during the assay.
(a) Plot Vo versus [S] and 1/V o versus 1/[S] for these data. Does penicillinase appear to obey Michaelis-Menten kinetics? If so, what is the value of K M ?
(b) What is the value of V max ?
(c) What is the turnover number of penicillinase under these experimental conditions? Assume one active site per enzyme molecule.
Fundamentals of biochemistry Life at the Molecular Level
ISBN: 978-0470547847
4th edition
Authors: Donald Voet, Judith G. Voet, Charlotte W. Pratt