Branched-chain ketoacid dehydrogenase

Rare patients respond to the administration of thiamine in large doses (10-30mg/day). The clinical course is even more mild than that of patients with intermittent disease. Thiamine is a cofactor for the branched-chain ketoacid dehydrogenase, and the presumed mutation involves faulty binding of the apoprotein to this vitamin. [Pg.672]

Branched-chain ketoacid dehydrogenase (metabolism of branched-chain amino acids)... [Pg.175]

Branched-Chain Ketoacid Dehydrogenase Deficiency (Maple Syrup Urine Disease)... [Pg.248]

Maple syrup urine disease (branched-chain ketoacid dehydrogenase)... [Pg.257]

Branched-chain ketoacid dehydrogenase Phenylalanine hydroxylase Tyrosine hydroxylase... [Pg.178]

TDP-dependent enzymes include transketolase, an enzyme component of the pentose shunt pathway, pyruvate dehydrogenase complex, and aKGDH a tricarboxylic acid cycle enzyme (Fig. 3). Branched-chain ketoacid dehydrogenases are also TDP-dependent. [Pg.106]

Metabolic intermediates and other local" effectors Many target specific enzymes, such as pyruvate dehydrogenase kinase and branched-chain ketoacid dehydrogenase kinase ... [Pg.426]

Boyer, B. Odessey, R. 1991) Arch. Bioch. Biop. 285, 1-7. Kinetic characterization of branched chain ketoacid dehydrogenase. [Pg.154]

BCKDC branched-chain ketoacid dehydrogenase complex (encoded by bkdAB)... [Pg.347]

Thiamin pyrophosphate (or thiamin diphosphate) is a coenzyme involved in (1) the oxidative decarboxylation of pyruvate to acetyl coenzyme A (enzyme pyruvate dehydrogenase), (2) the oxidative decarboxylation of a-ketoglutarate to succinyl coenzyme A (a-ketoglutarate dehydrogenase) in the tricarboxylic add cycle, (3) the pentose phosphate pathway (transketolase) and (4) the synthesis of branched-chain amino acids such as valine (branched-chain ketoacid dehydrogenase) in bacteria, yeasts and plants. [Pg.88]

The 2-ketoglutarate dehydrogenase (2-KGD) complex is composed of three separate enzymes 2-ketoglutarate decarboxylase, or El lipoate succi-nyltransferase, or E2 and lipoamide dehydrogenase, or E3. The complex catalyses the oxidation of 2-ketoglutarate to yield succinyl-CoA and NADH. 2-KGD deficiency together with pyruvate dehydrogenase deficiency and branched chain ketoacid decarboxylase deficiency has been ascribed to E3 deficiency because the three enzyme complexes have the E3 component in common. E3 deficiency will not be discussed. [Pg.215]

Paxton, R. Harris, R.A. Isolation of rabbit liver branched chain a-ketoacid dehydrogenase and regulation by phosphorylation. J. Biol. Chem., 257, 14433-14439 (1982)... [Pg.25]

Shimomura, Y. Kuntz, M.J. Suzuki, M. Ozawa, T. Harris, R.A. Monovalent cations and inorganic phosphate alter branched-chain a-ketoacid dehydrogenase-kinase activity and inhibitor sensitivity. Arch. Biochem. Biophys., 266, 210-218 (1988)... [Pg.26]

Doering, C.B. Coursey, C. Spangler, W. Danner, D.J. Murine branched chain a-ketoacid dehydrogenase kinase cDNA cloning, tissue distribution, and temporal expression during embryonic development. Gene, 212, 213-219 (1998)... [Pg.26]

Nellis, M.M. Doering, C.B. Kasinski, A. Danner, D.J. Insulin increases branched-chain cr-ketoacid dehydrogenase kinase expression in Clone 9 rat cells. Am. J. Physiol., 283, E853-E860 (2002)... [Pg.27]

Popov, K.M. Zhao, Y Shimomura, Y. Jaskiewicz, J. Kedishvili, N.Y Irwin, J. Goodwin, G.W. Harris, R.A. Dietary control and tissue specific expression of branched-chain cr-ketoacid dehydrogenase kinase. Arch. Biochem. Biophys., 316, 148-154 (1995)... [Pg.27]

Maple syrup urine disease (MSUD) is a recessive disorder in which there is a partial or complete deficiency in branched-chain o-ketoacid dehydrogenase, an enzyme that decarboxylates leucine, isoleucine, and valine (see Figure 20.10). These amino acids and their corre sponding a-keto acids accumulate in the blood, causing a toxic effect that interferes with brain functions. The disease is characterized by feeding problems, vomiting, dehydration, severe metabolic acidosis, and a characteristic maple syrup odor to the urine. If untreated, the disease leads to mental retardation, physical disabilities, and death. [Pg.270]

Correct answer = B. Alkaptonuria is a rare metabolic disease involving a deficiency in homogentisic acid oxidase, and the subsequent accumulation of homogentisic acid in the urine, which turns dark upon standing. The elevation of methylmalonate (due to methylmalonyl CoA mutase deficiency), phenylpyruvate (due to phenylalanine hydroxlyase deficiency), a-ketoisovalerate (due to branched-chain a-ketoacid dehydrogenase deficiency), and homocystine (due to cystathionine synthase deficiency) are inconsistent with a healthy child with darkening of the urine. [Pg.274]

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