Effects of @entity4313 on the hydrolysis of XXXX catalyzed by Streptococcus @entity689 .

@entity689 @entity167 @entity4313 @entity47797 @entity968
Regulation of the activity of @entity689 of Streptococcus sp. (group K) was evaluated by examining the effects of @entity4313 on the hydrolysis of colominic acids catalyzed by the @entity689 . Two kinds of @entity167 binding site, activation and inhibition sites, were proposed to exist. Competitive inhibition was observed with @entity4313 smaller than @entity968 #300 (average molecular weight: 300), so the inhibition site is considered to be the substrate binding site, the size of which was estimated to be 10 A in diameter. On the contrary, @entity968 larger than this size activated the enzyme by 1.5-1.8 times. The activity could be raised by binding of the @entity968 to the activation site. This activation was shown to be due solely to the decrease in the Michaelis constant, Km. The smaller @entity968 (#200 and #300) were also considered to bind to the activation site, although activation was not clearly observed due to compensation with inhibition. Strong substrate inhibition by @entity47797 was also observed. The activity of Streptococcus @entity689 was shown to be regulated intricately by the substrate @entity47797 and @entity4313 contained in the reaction medium.
