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：1984
卷号：81
期号：14
页码：4246-4249
DOI：10.1073/pnas.81.14.4246
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We have examined the affinity of two recently synthesized flavin analogs for the isoalloxazine binding site of riboflavin-binding protein (RBP). The results showed that pyrimidopteridines could bind to RBP (Kd 160-250 microM). This suggested that, at the FMN or FAD level, these analogs might also bind to other apoflavoproteins, thereby providing a high potential probe for flavin enzymology. In contrast, 4a,5-ring-opened isoalloxazines did not bind to RBP. However, 1,10a-ring-opened flavins bind with considerable avidity (Kd about 40 nM). Evidence is presented which indicates that the 4a,5-ring-opened species adopted a nonplanar configuration which, in turn, was responsible for the lack of affinity to RBP. Steric and electronic consequences of a 4a,5 ring opening are discussed in relation to flavin-dependent phenolic hydroxylases.
