[This corrects the article on p. 100 in vol. 41.].

Energy conservation in chemotrophic anaerobic bacteria.

Metabolic Reprogramming: A Cancer Hallmark Even Warburg Did Not Anticipate

http://xrm.phys.northwestern.edu/research/pdf_papers/2003/rosenthal_jmolbio_2003.pdf

Optimal determination of particle orientation, absolute hand, and contrast loss in single-particle electron cryomicroscopy.

alpha-Lipoic acid as a biological antioxidant.

http://www.somosbacteriasyvirus.com/powerhouse.pdf

Mitochondria: more than just a powerhouse.

This paper reports the discovery that the activity of the multienzyme pyruvate dehydrogenase complex from beef kidney mitochondria is regulated by a phosphorylation-dephosphorylation reaction sequence. The site of this regulation is the pyruvate dehydrogenase component of the complex. Phosphorylation and concomitant inactivation of pyruvate dehydrogenase are catalyzed by an ATP-specific kinase (i.e., a pyruvate dehydrogenase kinase), and dephosphorylation and concomitant reactivation are catalyzed by a phosphatase (i.e., a pyruvate dehydrogenase phosphatase). The kinase and the phosphatase appear to be regulatory subunits of the pyruvate dehydrogenase complex.

https://www.pnas.org/content/pnas/62/1/234.full.pdf

α-KETO ACID DEHYDROGENASE COMPLEXES, X. REGULATION OF THE ACTIVITY OF THE PYRUVATE DEHYDROGENASE COMPLEX FROM BEEF KIDNEY MITOCHONDRIA BY PHOSPHORYLATION AND DEPHOSPHORYLATION

The activity of the multienzyme pyruvate dehydrogenase complexes, isolated from mitochondria of beef kidney, beef heart, and pork liver, is regulated by phosphorylation and dephosphorylation. Phosphorylation and concomitant inactivation of each of the three complexes are catalyzed by an ATP-specific kinase, and dephosphorylation and concomitant reactivation are catalyzed by a phosphatase. The phosphatase has been separated from the other component enzymes of each pyruvate dehydrogenase complex, and the three phosphatases are functionally interchangeable. The kinase has been isolated from the beef kidney complex, and it is functional with the beef heart and pork liver complexes. ADP is competitive with ATP, and the ADP effect is more pronounced with the kidney kinase than with the liver and heart kinases. Pyruvate protects strongly the heart and liver pruvate dehydrogenase complexes and, to a lesser extent, the kidney complex against inactivation by ATP. Pyruvate apparently exerts its effect on the pyruvate dehydrogenase component of the complex, rather than on the kinase.

https://www.pnas.org/content/pnas/64/1/227.full.pdf

α-KETO ACID DEHYDROGENASE COMPLEXES, XI. COMPARATIVE STUDIES OF REGULATORY PROPERTIES OF THE PYRUVATE DEHYDROGENASE COMPLEXES FROM KIDNEY, HEART, AND LIVER MITOCHONDRIA

https://science.sciencemag.org/content/sci/114/2952/93.full.pdf

Crystalline α-Lipoic Acid: A Catalytic Agent Associated with Pyruvate Dehydrogenase

Publisher Summary The chapter describes assay method, purification procedure, and properties of the α- ketoglutarate dehydrogenase enzyme. This enzyme has been isolated from pig heart muscle, Escherichia coli, and beef kidney mitochondria as multienzyme complexes with molecular weights of several million. The E. coli α-ketoglutarate dehydrogenase complex is separated in three enzymes, α-ketoglutarate dehydrogenase (E1), dihydrolipoyl transsuccinylase (E2), and dihydrolipoyl dehydrogenase (E3), and the complex is reconstituted from the isolated enzymes. There is as no sensitive and convenient assay for the a-ketoglutarate dehydrogenase complex that may be used at all levels of purity of the enzyme complex. The DPN reduction assay described is the only reliable assay for the intact complex however it is not suitable for crude preparations that contain DPNH oxidase. Assays for the three component enzymes of the a-ketoglutarate dehydrogenase complex are described, but these assays do not distinguish between the free and combined enzymes. Thus, the ferricyanide reduction assay described provides an estimate of the activity of the α-ketoglutarate dehydrogenase component (E1) of the complex.

Lester J. Reed

Papers

α-KETO ACID DEHYDROGENASE COMPLEXES, X. REGULATION OF THE ACTIVITY OF THE PYRUVATE DEHYDROGENASE COMPLEX FROM BEEF KIDNEY MITOCHONDRIA BY PHOSPHORYLATION AND DEPHOSPHORYLATION

α-KETO ACID DEHYDROGENASE COMPLEXES, XI. COMPARATIVE STUDIES OF REGULATORY PROPERTIES OF THE PYRUVATE DEHYDROGENASE COMPLEXES FROM KIDNEY, HEART, AND LIVER MITOCHONDRIA

Crystalline α-Lipoic Acid: A Catalytic Agent Associated with Pyruvate Dehydrogenase

[12] α-ketoglutarate dehydrogenase complex from Escherichia coli

Regulation of pyruvate dehydrogenase kinase and phosphatase by acetyl-CoA/CoA and NADH/NAD ratios.