1. d-Lactic Acidosis and Selected Cerebellar Ataxias
Shelley A. Cross, M.D. 
Mayo Clinic Proceedings 
Volume 59, Issue 3, Pages (March 1984)
DOI: /S (12)
Copyright © 1984 Mayo Foundation for Medical Education and Research Terms and Conditions

2. Fig. 1
Diagrammatic representation of pyruvate metabolism. Major pathways of pyruvate formation and breakdown are shown. Words and phrases in parentheses refer to overall pathways. Abbreviations in parentheses refer to specific enzymes: GPT = glutamic-pyruvic transaminase; LDH = lactate dehydrogenase; PC = pyruvate carboxylate; and PDHC = pyruvate dehydrogenase complex. ADP = adenosine diphosphate; ATP = adenosine triphosphate; Pi = inorganic phosphate.
(From Blass JP.17 By permission.)
Mayo Clinic Proceedings  , DOI: ( /S (12) )
Copyright © 1984 Mayo Foundation for Medical Education and Research Terms and Conditions

3. Fig. 2
Overview of pyruvate dehydrogenase complex. Diagram illustrates coordinated action of three enzymes in pyruvate dehydrogenase complex. En1 is pyruvate dehydrogenase, a thiamine pyrophosphate-dependent enzyme that catalyzes decarboxylation of pyruvate to produce CO2 (from the number 1 carbon atom of pyruvate) and active aldehyde (hydroxyethylthiamine). En2 is lipoate acetyltransferase, a lipoic acid-dependent enzyme that catalyzes oxidative transfer of the two-carbon unit from the first enzyme to coenzyme A and forms acetylcoenzyme A. En3 is lipoamide dehydrogenase, a flavin-linked enzyme that reoxidizes lipoic acid to the oxidized form and is itself reoxidized by the oxidized form of nicotinamide adenine dinucleotide (NAD+). Kinase inactivates the complex by catalyzing a phosphorylation of En1. The complex is reactivated by dephosphorylation by a phosphatase. Control of the kinase-phosphatase equilibrium is complex; activation is favored by, among other factors, decrease in the ratio of adenosine triphosphate (ATP) to adenosine diphosphate (ADP) and an increase in Mg+ + concentration. The products of the reaction, the reduced form of nicotinamide adenine dinucleotide (NADH) and acetylcoenzyme A, are also inhibitors of the pyruvate dehydrogenase complex. FAD = flavin-adenine dinucleotide; FADH2 = reduced form of FAD.
(From Blass JP.17 By permission.)
Mayo Clinic Proceedings  , DOI: ( /S (12) )
Copyright © 1984 Mayo Foundation for Medical Education and Research Terms and Conditions