l-Threonine deaminase in marine planktonic algae
| العنوان: | l-Threonine deaminase in marine planktonic algae |
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| المؤلفون: | Naval J. Antia, Robert S. Kripps |
| المصدر: | Archiv f�r Mikrobiologie. 94:29-46 |
| بيانات النشر: | Springer Science and Business Media LLC, 1973. |
| سنة النشر: | 1973 |
| مصطلحات موضوعية: | media_common.quotation_subject, Allosteric regulation, Deamination, Substrate (chemistry), General Medicine, Biology, Plankton, biology.organism_classification, Biochemistry, Microbiology, Competition (biology), Algae, Dehydratase, Genetics, Threonine, Molecular Biology, media_common |
| الوصف: | 1. The “biosynthetic” l-threonine (deaminating) dehydratase activity of 7 marine planktonic species from 5 classes of algae showed high substrate specificity toward l-threonine, with the exception of one alga. The algal extracts deaminated l-serine and l-allothreonine at rates which were 20–25 and 5–10%, respectively, of that of l-threonine, and these reaction were inhibited by l-isoleucine. d-Threonine, d-serine, l-homoserine, and l-O-methylthreonine were ineffective as substrates. 2. Extracts of the cryptophyte Chroomonas salina were exceptional in showing about twice the activity with l-serine relative to l-threonine. The reaction with l-serine was insensitive to inhibition by l-isoleucine and differed, in several respects from that with l-threonine. It was inferred that this algal extract contains a specific l-serine deaminase in addition to the regular l-threonine deaminase. 3. The rate of deamination of l-threonine by the algal extracts was not affected by the simultaneous presence of l-allothreonine but was markedly inhibited by l-serine and l-homoserine. 4. Kinetic studies of the effects of graded concentrations of the substrate analogs at a fixed (saturating) substrate level or of substrate concentration at fixed analog levels indicated that l-serine inhibited the threonine deamination by irreversible competition with the substrate, whilst l-homoserine affected this reaction by an unknown (presumably allosteric) mechanism not involving substrate competition. |
| تدمد: | 1432-072X 0302-8933 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::4bf1084ff672a12f488f9d5a9e24a749 https://doi.org/10.1007/bf00414076 |
| حقوق: | CLOSED |
| رقم الأكسشن: | edsair.doi...........4bf1084ff672a12f488f9d5a9e24a749 |
| قاعدة البيانات: | OpenAIRE |
Find this article in full text from Springer Verlag. | تدمد: | 1432072X 03028933 |
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