期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1981
卷号：78
期号：9
页码：5886-5889
DOI：10.1073/pnas.78.9.5886
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Synaptic plasma membranes were prepared from rat cerebral cortex to determine if thiamine was localized in the membranes. The synaptosomes, prepared by discontinuous sucrose gradient centrifugation, were subjected to osmotic shock at pH 9.5 for 10--15 min and subfractionated on a discontinuous sucrose gradient. The two membrane fractions that were obtained were free of contamination by mitochondrial membrane and soluble fractions. In order to ensure specificity, thiamine was assayed fluorometrically before and after the addition of thiaminase I (thiamin:base 2-methyl-4-aminopyrimidine-5-methenyltransferase, EC 2.5.1.2 ). The thiamine content of the two membrane fractions was 9 and 10 pmol/mg protein.
