Fiehn N E, Moe D
Scand J Dent Res. 1981 Dec;89(6):450-7. doi: 10.1111/j.1600-0722.1981.tb01708.x.
Supragingival human dental plaque was collected from patients with evidence of caries. The plaque was frozen and stored at -20 degrees C. Pooled plaque was homogenized in acetate buffer pH 5.0 in an ice-water bath. By incubating the homogenate at pH 5.0 with [U-14C]-sucrose the formation of glucose and fructose was followed. Incubation in acetate buffer at pH 5.0 eliminated the glycosyltransferase activities and the glycolytic pathway. Normal Michaelis-Menten kinetics were observed until about 40 mM sucrose. At higher concentration of sucrose, excess substrate inhibition occurred. Storage of the homogenate at -20 degrees C resulted in decrease of the invertase activity with time.
从有龋齿迹象的患者中收集龈上人类牙菌斑。将菌斑冷冻并储存在-20℃。将混合的菌斑在冰浴中的pH 5.0醋酸盐缓冲液中匀浆。通过在pH 5.0下用[U-14C]-蔗糖孵育匀浆来追踪葡萄糖和果糖的形成。在pH 5.0的醋酸盐缓冲液中孵育消除了糖基转移酶活性和糖酵解途径。直到约40 mM蔗糖都观察到正常的米氏动力学。在更高的蔗糖浓度下，出现了底物过量抑制。将匀浆储存在-20℃会导致转化酶活性随时间降低。
