Fong D, Rutherford C L
J Bacteriol. 1978 May;134(2):521-7. doi: 10.1128/jb.134.2.521-527.1978.
Individual aggregates, migrating pseudoplasmodia, and sorocarps of Dictyostelium discoideum were assayed for proteolytic activities by colorimetric and fluorometric techniques. Cathepsin D-like and cathepsin B-like acid protease activities were found to decrease throughout development, but the patterns of decrease were different for the two enzymes. A gradual decrease was found for cathepsin D, whereas a sharp decrease between aggregates and migrating pseudoplasmodia was detected for cathepsin B. By using microdissection techniques and fluorometric assays for amino acids and peptides, prestalk cells and prespore cells exhibited no difference in cathepsin D activity, whereas cathepsin B activity was higher in the prestalk cells. Similarly, stalk cells and spores in the sorocarps showed no difference in cathepsin D activity, but showed a fivefold higher cathepsin B activity in the stalk cells. This finding suggests a possible role for cathepsin B in stalk cell differentiation.
采用比色法和荧光法技术，对盘基网柄菌的单个聚集体、迁移的伪原质团和子实体进行蛋白水解活性检测。发现组织蛋白酶D样和组织蛋白酶B样酸性蛋白酶活性在整个发育过程中均下降，但两种酶的下降模式不同。组织蛋白酶D呈逐渐下降，而组织蛋白酶B在聚集体和迁移的伪原质团之间急剧下降。通过使用显微切割技术以及对氨基酸和肽进行荧光检测，前柄细胞和前孢子细胞在组织蛋白酶D活性上没有差异，而前柄细胞中的组织蛋白酶B活性更高。同样，子实体中的柄细胞和孢子在组织蛋白酶D活性上没有差异，但柄细胞中的组织蛋白酶B活性高五倍。这一发现表明组织蛋白酶B在柄细胞分化中可能发挥作用。
