... treatment above assumes that there are no differences in heat capac-
ity between native and denatured states of an enzyme and that the heat
capacity remains constant throughout the temperature ... stability, enzyme solutions are
incubated at a particular temperature and aliquots removed at the appro-
priate times. Enzyme activity in these samples is then measured at the
enzyme s temp...
... V
max
/52
3.4 Practical Example / 53
3.5 Determination of Enzyme Catalytic Parameters
from the Progress Curve / 58
ENZYME KINETICS
A Modern Approach
ALEJANDRO G. MARANGONI
Department of Food ... new ways of analyzing kinetic data, particularly in the study of
pH effects on catalytic activity and multisubstrate enzymes. Since a large
proportion of traditional enzyme kinetics...
... Changes in the reaction rate constant for an acid/base-catalyzed reaction as
a function of pH. A negative sloping line (slope =−1) as a function of increasing pH is
indicative of an acid-catalyzed ... for example, the reaction A → B →
C. Usually, equations in differential or algebraic form are fitted to indi-
vidual data sets, A, B, and C and a set of parameter estimates obtained.
2...
... statistic:
χ
2
=
n
i=1
(y
i
−ˆy
i
)
2
s
2
i
=
n
i=1
w
i
(y
i
−ˆy
i
)
2
(1.125)
Consider a typical experiment where the value of a dependent variable is
measured several times at a particular value of the independent variable.
From these repeated determinations, a mean and variance ... Exact Analytical Solution (Non-Steady-State
Approximation)
Exact analytical solutions for the rea...
... is appropriate. When more
than two values are compared, a one-way analysis of variance (ANOVA),
TABLE 4.2 Rate of Hydration of Fumarate to Malate by Fumarase at various
Substrate Concentrations
a
Velocity ... V
∗
max
and K
∗
s
correspond, respectively, to apparent enzyme maxi-
mum velocity and apparent enzyme substrate dissociation constant at a
particular pH. For the model above, V...
... as
v
V
max
=
[B]
K
+ [B]
(7. 12)
where
V
max
=
V
max
[A]
K
BA
+ [A]
(7. 13)
and
K
=
K
A
s
K
AB
+ K
AB
[A]
K
BA
+ [A]
=
K
AB
(K
A
s
+ [A] )
K
BA
+ [A]
(7. 14)
From determinations of K
and V
max
at ... complexes
EAB (K
AB
and K
BA
), and the enzyme mass balance are, respectively,
v = k
cat
[EAB] (7. 7)
K
A
s
=
[E] [A]
[EA]
K
B
s
=
[E][B]
[EB]
(7. 8)
K
BA
=
[EB] [...
... exponential term, and the shape of the
curve approaches that of a straight line. Valuable information can be
gained from analysis of the early and late stages of this reaction.
11.2.1 Early Stages ... plot for an interfa-
cial enzyme.
various parameters in Eq. (10.9) on the velocity of a reaction catalyzed
by an interfacial enzyme. As the enzyme interface dissociation constant
increas...
... K
i
of an alter-
nate substrate. Addition of an alternate substrate inhibitor to an enzyme
assay results in an exponential decrease in rate to some final steady-
state turnover of substrate (Fig. ... Finer-Moore, Y. Wataya, and D. V. Santi,
Biochemistry 33, 1508 6–1 5094 (1994).
Groutas, W. C., R. Kuang, R. Venkataraman, J. B. Epp, S. Ruan, and O. Prakash,
Biochemistry 36, 473 9–4 75 0...
... lysine–proline–alanine–glutamic acid–phenylalanine–
phenylalanine (NO
2
)–alanine–leucine.
c
ss2, substrate consisting of the peptide leucine–serine–phenylalanine (NO
2
)–norleucine–leucine–
methyl ... than either valine
and serine mutants, which had comparable catalytic constants. Compared
to valine and serine, alanine has the smallest van der Waals volume and
accessible surface area. Theref...