Diffusion-Controlled Enzymes and Reaction Speed

Catalytically perfect enzymes are enzymes that speed up biochemical reactions at very high rates. The idea was first proposed by W. J. Albery and J. R. Knowles in 1976. These enzymes have catalytic efficiency values of about 10^8 to 10^9 M^-1 s^-1 and are also called diffusion-controlled enzymes because diffusion of the subs...

催化效率达到完美的酶具有最高的催化效率，其转换数 k_cat 较高，且对底物的亲和力强，即米氏常数 K_M 较低。
 

k_cat 与 K_M 的比值用于衡量催化效率。对于催化完美的酶，该值范围为每摩尔底物每秒 10⁸ 到 10⁹。
 

底物扩散是由分子运动引起的底物分子的持续移动。底物必须在细胞内扩散，才能与其酶相互作用。
 

催化完美酶的反应速率仅受限于底物扩散进入活性位点或产物从活性位点释放的速度。一些酶通过静...