Kilpatrick D C, Schmidt J A, Stirling J L, Pacy J, Jones G E
J Embryol Exp Morphol. 1980 Jun;57:189-201.
Development of the cellular slime mould Dictyostelium discoideum strain NC4, in the presence of alpha-chymotrypsin (3 mg/ml) is reversibly arrested at the tight aggregate stage (10/12 h). Pronase has a similar effect, but trypsin only retards normal development by about five hours. Normally developing cells are susceptible to alpha-chymotrypsin if they are transferred into its presence at any time up to the tight aggregate stage (10-12 h). Transfer after this stage does not affect the appearance of fruiting body structures in the normal time (24 h). Electron microscopy showed the ultrastructure of alpha-chymotrypsin-blocked aggregates after starvation for 24 h to be consistent with a block at 10-12 h of normal development. Poorly developed prespore vacuoles, having thin incomplete walls and a paucity of electron-dense material, are present in some cells. No angular vacuolated cells characteristic of stalk cells are visible. Fruiting bodies formed in the presence of a alpha-chymotrypsin, either as minority structures when the enzyme is added before 10-12 h of normal development, or as the majority structures on later enzyme addition, were found to be abnormal. Normal stalks were formed but the spores were immature. Prespore vacuoles were present, though disrupted, and the cells were not encapsulated by spore walls. The electronegativity of intact slime mould amoebae was significantly reduced, and material containing L-[6-3H]-fucose and [1-14C]leucine was removed from the cell surface on alpha-chymotrypsin treatment. Few plasma membrane proteins were affected, however, and staining of polyacrylamide gels for glycopeptides using Con A-peroxide binding also showed little change.
在存在α-胰凝乳蛋白酶（3毫克/毫升）的情况下，盘基网柄菌NC4细胞黏菌菌株的发育在紧密聚集阶段（10/12小时）被可逆性阻滞。链霉蛋白酶有类似作用，但胰蛋白酶仅使正常发育延迟约5小时。正常发育的细胞在直至紧密聚集阶段（10 - 12小时）的任何时间转移到α-胰凝乳蛋白酶存在的环境中时，都会对其敏感。在此阶段之后转移并不影响在正常时间（24小时）出现子实体结构。电子显微镜显示，饥饿24小时后α-胰凝乳蛋白酶阻滞的聚集体的超微结构与正常发育10 - 12小时时的阻滞情况一致。一些细胞中存在发育不良的前孢子液泡，其壁薄且不完整，电子致密物质稀少。未见特征性的成柄细胞的角状液泡化细胞。发现在α-胰凝乳蛋白酶存在下形成的子实体是异常的，当在正常发育10 - 12小时之前添加该酶时，子实体作为少数结构形成，而在后期添加酶时则作为多数结构形成。形成了正常的柄，但孢子不成熟。存在前孢子液泡，尽管已被破坏，且细胞未被孢子壁包裹。完整黏菌变形虫的负电性显著降低，经α-胰凝乳蛋白酶处理后，含有L-[6 - 3H]-岩藻糖和[1 - 14C]亮氨酸的物质从细胞表面被去除。然而，很少有质膜蛋白受到影响，并且使用伴刀豆球蛋白-过氧化物结合对聚丙烯酰胺凝胶上的糖肽进行染色也显示变化很小。
