Appeal No. 2005-1745
Application No. 09/161,680
of substrate is increased, the rate at which product is formed also increases up to
a maximum value. . . . At that point the enzyme molecule is saturated with
substrate [Alberts,9 p. 131, para. 1].
The KM “is equal to the substrate concentration at which the initial reaction velocity
is half maximal.” Lehninger, p. 193, para. 1. Thus, “[a] low KM value means that the
enzyme reaches its maximum catalytic rate at a low concentration of substrate and
generally indicates that the enzyme binds its substrate very tightly.” Alberts, p. 131,
para. 2. Accordingly, the disclosure on page 3, lines 45-46, of the specification, as
originally filed, that the KM value of the enzyme to the substrate was high, means that the
enzyme had very little affinity for the substrate. Nevertheless, to have a KM value at all,
there must be some binding of the enzyme and substrate, albeit with very low affinity
(i.e., high KM). Thus, the statement in the specification with respect to the enzyme
having any KM value appears to be inconsistent with the statement that the enzyme was
previously unable to convert the enzyme.
The catalytic activity (kcat) is a quantitative measure, which according to the
appellants, is the rate at which the substrate is converted into product by the enzyme.
Amendment received April 15, 2003, p. 3. The rate at which the product is formed
depends, inter alia, on the concentration of substrate and on the enzyme itself, and on
the concentration of the enzyme. Alberts, p. 61. Thus, lack of catalytic activity is one
9 Alberts et al. (Alberts), in Molecular Biology of the Cell, Garland Publishing, Inc.,
New York and London (1983). Relevant pages attached.
21
Page: Previous 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next
Last modified: November 3, 2007