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：1974
卷号：71
期号：2
页码：469-473
DOI：10.1073/pnas.71.2.469
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Alkaline phosphatase (EC 3.1.3.1 ) containing m-flurotyrosine has been prepared from E. coli grown in the presence of m-flurotyrosine. The kinetic properties of the m-fluorotyrosine enzyme measured with p-nitrophenylphosphate at pH 8.0 and dinitrophenylphosphate at pH 5.5 are essentially the same as those of normal alkaline phosphatase. However, the ability of the m-fluorotyrosine protein to refold active enzyme after acid denaturation, while unchanged at pH 5.8, was markedly decreased at pH 7.6. This result implies that the tyrosines must be in their protonated form for the protein to refold, reassociate, and take on zinc. The 19F nuclear magnetic resonance spectrum of m-fluorotyrosine alkaline phosphatase contains resolved resonances corresponding to different chemical environments for each m-fluorotyrosine in the folded protein. This demonstrates that 19F nuclear magnetic resonance spectroscopy of enzymes specifically labeled with 19F, even with enzymes as large as alkaline phosphatase (molecular weight, 86,000), will provide a very valuable probe for conformational changes in proteins.
