ACTIONS OF TWO TYPES OF THIAMINASE ON THIAMIN AND ITS ANALOGUES
ACTIONS OF TWO TYPES OF THIAMINASE ON THIAMIN AND ITS ANALOGUES
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两种硫胺素酶对硫胺素及其类似物的作用
DOI：
10.1111/j.1749-6632.1982.tb31193.x
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发表时间：
1982
影响因子：
5.2
通讯作者：
K. Murata
中科院分区：
文献类型：
--
作者：
K. Murata
硫胺酶I(EC2.5.1.2)广泛存在于贝类、淡水鱼(主要存在于内脏)、蕨类以及少量的海鱼和植物中，存在于芽孢杆菌和梭状芽孢杆菌等微生物中。硫胺酶I1(EC 3.5.99.2)在其他类型的芽孢杆菌、毛孢子菌、念珠菌、卵孢子菌和其他生物体中都能产生。他们发现的历史在其他地方已经有了详细的描述。它们在活细胞中通常是不活跃的，但当它们在pH 4-8左右的水溶液中均质或从细胞或微生物排泄到培养基中时，它们就会激活。硫胺素酶I通过与有机碱以及与硫胺素的嘧啶部分的亚甲基上的亲核取代的巯基化合物的交换反应催化硫胺素的裂解。另一方面，硫胺酶I1只是加速硫胺素的水解，生成其嘧啶和噻唑部分。本文介绍了硫胺素与各种有机碱性或硫醇化合物的大量实验观察和硫胺酶I与各种有机硫醇化合物的交换产物的鉴定，以及从硫胺素和细菌硫胺酶I的反应混合物中分离出硫胺素的嘧啶和噻唑部分。本文综述了这两类硫胺酶对硫胺素及其类似物或衍生物，包括硫胺素焦磷酸(TPP)9的作用方式，并介绍了硫胺酶的一些新工作。
It has been well established by many workers that thiaminase I (EC 2.5.1.2) is found in shellfish, fresh-water fish (mainly in viscera), fern, and a limited number of sea fish and plants, and produced in microorganisms such as Bacillus and Clostridium. Thiaminase I1 (EC 3.5.99.2) is produced in other types of Bacillus, Trichosporon, Candidu, Oospora, and other organisms. The history of their discoveries has been described in detail elsewhere.'" They are usually inactive in living cells, but are activated when they are homogenized in a water solution around pH 4-8 or excreted from cells or microorganisms into the medium. Thiaminase I catalyzes the cleavage of thiamin by an exchange reaction with an organic base as well as with a sulfhydryl compound involving a nucleophilic displacement on the methylene group of the pyrimidine moiety of thiamin. On the other hand, thiaminase I1 simply accelerates the hydrolysis of thiamin into its pyrimidine and thiazole moieties. Many experimental observations and the identification of a number of exchange products of thiamin with various organic basic or thiol compounds by thiaminase I, and the isolation of pyrimidine and thiazole moieties of thiamin from a reaction mixture of thiamin and bacterial thiaminase I I were introduced in the abovementioned review^.^.' In this paper, modes of action of the two types of thiaminase on thiamin and its analogues or derivatives,+* including thiamin pyrophosphate (TPP)9 will be summarized and some additional works of thiaminase will be introduced."."