Hecker L I, Sussman A S
J Bacteriol. 1973 Aug;115(2):592-9. doi: 10.1128/jb.115.2.592-599.1973.
An association of trehalase with the innermost wall (endosporium) of ascospores of Neurospora is suggested, because this enzyme could be lyophilized in the presence of various wall components and heated in this dried state at 65 C without loss of activity. Ground ascospore walls, purified mycelial walls, a wall fraction consisting of protein, glucan and polygalactosamine, or bovine serum albumin stabilize trehalase under these conditions. No other substances tested protected as well as the above materials. Immunofluorescent labeling of trehalase shows that it is localized in the endosporium. Therefore, it is most probable that in dormant ascospores of Neurospora, trehalase, and its substrate, trehalose, are physically separated. Trehalose is located in the cytoplasm, whereas trehalase resides within the protein and carbohydrate matrix of the innermost major cell wall layer of the ascospore. The association with the cell wall protects the enzyme against the heating which is necessary to activate germination. Activation, whether by heat or chemical treatment (furfural), probably involves an increase in the permeability of the ascospore plasma membrane allowing trehalose to diffuse to the vicinity of its hydrolase, thereby providing the energy and intermediates for germination.
有人提出，海藻糖酶与脉孢菌子囊孢子的最内层壁（内膜）有关联，因为这种酶能在存在各种壁成分的情况下进行冻干，并在这种干燥状态下于65℃加热而不失活。磨碎的子囊孢子壁、纯化的菌丝体壁、一种由蛋白质、葡聚糖和聚半乳糖胺组成的壁组分，或牛血清白蛋白在这些条件下能稳定海藻糖酶。所测试的其他物质都没有上述材料保护得好。海藻糖酶的免疫荧光标记显示它定位于内膜。因此，最有可能的是，在脉孢菌的休眠子囊孢子中，海藻糖酶及其底物海藻糖在物理上是分离的。海藻糖位于细胞质中，而海藻糖酶存在于子囊孢子最内层主要细胞壁层的蛋白质和碳水化合物基质中。与细胞壁的结合保护酶免受激活萌发所需的加热影响。无论是通过加热还是化学处理（糠醛）激活，可能都涉及子囊孢子质膜通透性的增加，使海藻糖扩散到其水解酶附近，从而为萌发提供能量和中间产物。
