三种真菌酶的碳水化合物单元在其抗脱水方面的功能。
The function of the carbohydrate units of three fungal enzymes in their resistance to dehydration.
作者信息
Darbyshire B
机构信息
Commonwealth Scientific and Industrial Research Organization, Division of Irrigation Research, Griffith, New South Wales 2680, Australia.
出版信息
Plant Physiol. 1974 Nov;54(5):717-21. doi: 10.1104/pp.54.5.717.
Glucose oxidase (from Aspergillus niger), glucoamylase (from Rhizopus spp.), and cellulase (from Aspergillus niger) of fungal origin are all glycosylated proteins. Dehydration of the three enzymes to a range of water potentials did not affect their activity. However, when more than 10% of the carbohydrate associated with the molecules was removed by periodate oxidation, the enzymes were highly susceptible to dehydration when compared with oxidized controls. Polyvinyl pyrrolidone and Dextran T500 protected the three enzymes in their oxidized state against the effects of dehydration.The carbohydrate units of the enzymes have a function in protecting the enzymes from dehydration and this may be a contributing factor to the survival of microorganisms in environments of low water potentials. The involvement of water associated with the enzyme molecules due to the presence of carbohydrate units is considered to be the protecting mechanism.
来源于真菌的葡萄糖氧化酶（黑曲霉）、糖化酶（根霉属）和纤维素酶（黑曲霉）都是糖基化蛋白。将这三种酶脱水至一系列水势范围不会影响其活性。然而，当通过高碘酸盐氧化去除与分子相关的超过10%的碳水化合物时，与氧化对照相比，这些酶对脱水高度敏感。聚乙烯吡咯烷酮和葡聚糖T500保护处于氧化状态的这三种酶免受脱水影响。酶的碳水化合物单元具有保护酶免受热脱水的功能，这可能是微生物在低水势环境中存活的一个促成因素。由于碳水化合物单元的存在而与酶分子相关的水的参与被认为是保护机制。
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