(Z)-Tetrahydropteroyltriglutamate and (Z)-tetrahydropteroylhexaglutamate were prepared and tested as substrates for thymidylate synthetase (EC 2.1.1.6) (methylenetetrahydrofolate: deoxyuridylate C-methyltransferase) from Zactobacillus casei. Both tetrahydropteroylpolyglutamates were more effective substrates than (Z)-tetrahydropteroylglutamate, enhancing the reaction rate 3-fold when compared a...

A progressive loss of photosynthetic activity occurred when cells of Anacystis nidulans and Coccochloris peniocystis were incubated in increasing concentrations of osmotica from 0.2 to 0.7 M, and there was a release of pteridine from the cells proportional to the loss of photosynthetic activity.

Nitric oxide (NO) is synthesised from L-arginine by the enzyme NO synthase (NOS). The complex reaction involves the transfer of electrons from NADPH, via the flavins FAD and FMN in the carboxy-terminal reductase domain, to the haem in the amino-terminal oxygenase domain, where the substrate L-arginine is oxidised to L-citrulline and NO. The haem is essential for dimerisation as well as NO produ...

While the existence of a molybdenum cofactor common to nitrate reductase, xanthine oxidase, and sulfite oxidase has been finnly established by studies from several laboratories (1-6), the nature of the molecule has not been elucidated. Information available to date has shown that the molybdenum cofactor complex is noncovalently attached to the proteins (2, 4) and is probably a small, dialyzable...

The structure of chicken liver dihydrofolate reductase (5,6,7,8-tetrahydrofolate:NADP+ oxidoreductase (EC 1.5.1.3)), in a ternary complex with NADPH and a phenyltriazine inhibitor, has been determined at a nominal resolution of 2.9 A. Overall backbone chain folding is very similar to that observed in Escherichia coli and Lactobacillus casei dihydrofolate reductases. About 70% of the additional ...

development of a stool antigen immunoassay to detect helicobacter pylori infection requires monoclonal antibody against the specific antigen. alkylhydroperoxide reductase (ahpc) of helicobacter pylori has been described as a specific and unique enzyme for h. pylori and therefore, both h. pylori ahpc and anti-ahpc could be useful in the development of serologic and stool antigen tests, for detec...