Cystathione beta-synthase

M. Meier, M. Janosik, V. Kery, J.P. Kraus, and P. Burkhard, Structure of human cystathione beta-synthase a unique pyridozal 5 -phosphate-dependent heme protein. EMBO J. 20, 3910-3916 (2001). 

M. Nordstrom and T. Kjellstrom, Age dependency of cystathione beta-synthase activity in human fibroblasts in homocysteinemia and atherosclerotic vascular disease. Atherosclerosis 94, 213-221 (1992). 

Other examples of PLP-requiring enzymes are the amino acid decarboxylases that lead to formation of amines, including several that are functional in nervous tissue (e.g., epinephrine, norepinephrine, serotonin, and y-aminobutyrate) cysteine desulfhydrase and serine hydroxymethyltransferase, which use PLP to effect the loss or transfer of amino acid side chains phosphorylase, which catalyzes phosphorolysis of the a-1,4-linkages of glycogen and cystathione beta-synthase in the transsulfiiration pathway of homocysteine. Additionally the biosynthesis of heme depends on the early... 

Classical homocystinuria is a rare inherited disorder, caused by the deficiency of cystathione beta-synthase resulting in accumulation of methionine it can cause mental retardation, eye problems and thrombosis. Dietary management aims to prevent accumulation of methionine by means of a low-methionine diet and by supplementing the diet with a methionine amino acid mixture. 

Homocystinuria. An inherited autosomal recessive disorder of homocysteine metabolism (1/200000 births) caused by mutations in the cystathione beta synthase (CBS) gene that disrupts the normal activity of CBS. Homocystinuria patients have highly elevated plasma homocysteine levels and are at increased early risk of thrombotic/vascular events. Homocystinuria can be more rarely caused by mutations in other genes involved in homocysteine metabolic pathways. 

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