Extensive work with human hemoglobins indicates that the typical variant hemoglobin differs from normal hemoglobin by a single amino acid substitution. MAutational studies with E. coli tryptophan synthetase have shown that variants of this protein also owe their origin to single replacement of an amino acid. Using biochemical and genetic recombination techniques, it has been shown that the site...

Human brain turnors removed from 126 patients were histochemically examined and following results were obtained. 1. In general, alkaline phosphatase activity is decreased in poorly differentiated gliomas, but is not related to the tumor cell infiltration. 2. All the cases of alkaline phosphatase negative gliomas have poor reconvalescent course and most of the positive cases show good reconvales...

Identification of regulatory mutations of glutamate dehydrogenase (GDH) in a form of congenital hyperinsulinism (GDH-HI) is providing a model for basal insulin secretion (IS) and amino acid (AA)-stimulated insulin secretion (AASIS) in which glutaminolysis plays a key role. Leucine and ADP are activators and GTP is an inhibitor of GDH. GDH-HI mutations impair GDH sensitivity to GTP inhibition, l...

BACKGROUND Activating mutations in the GLUD1 gene (which encodes for the intra-mitochondrial enzyme glutamate dehydrogenase, GDH) cause the hyperinsulinism-hyperammonaemia (HI/HA) syndrome. Patients present with HA and leucine-sensitive hypoglycaemia. GDH is regulated by another intra-mitochondrial enzyme sirtuin 4 (SIRT4). Sirt4 knockout mice demonstrate activation of GDH with increased amino ...

Pathophysiological effects of nitric oxide (NO)-deficient hypertension are much better known than are the potential morphological changes. Hearts and main arteries were studied in 15 week old male Wistar rats administered NG-nitro-L-arginine methyl ester (L-NAME) for 4 weeks. A does of 40 mg/kg/day increased systolic arterial pressure by 30%, while heart rate decreased by 20%. Heart/body weight...

The gene encoding the valine (branched-chain amino acid) dehydrogenase (Vdh) from Streptomyces coelicolor has been characterized as follows. The vdh gene was identified by hybridization to a specific oligodeoxynucleotide that was synthesized on the basis of the N-terminal amino acid sequence of purified Vdh. Nucleotide sequence analysis predicts that the vdh gene contains a 364-amino-acid open ...

BkdR is the transcriptional activator of the bkd operon, which encodes the four proteins of the branched-chain keto acid dehydrogenase multienzyme complex of Pseudomonas putida. In this study, hydroxyl radical footprinting revealed that BkdR bound to only one face of DNA over the same region identified in DNase I protection assays. Deletions of even a few bases in the 5' region of the BkdR-bind...

We have developed an in vitro system for detailed analysis of reversible phosphorylation of the plant mitochondrial pyruvate dehydrogenase complex, comprising recombinant Arabidopsis thalianaα2β2-heterotetrameric pyruvate dehydrogenase (E1) plus A. thaliana E1-kinase (AtPDK). Upon addition of MgATP, Ser292, which is located within the active-site loop structure of E1α, is phosphorylated. In add...

We screened a tomato (Lycopersicon esculentum L.) cDNA library (1.3 x 106 plaque-forming units [7]) with a polymerase chain reaction fragment that was thought to be a specific probe for a shikimate dehydrogenase, and we isolated 11 independent clones (Table I). The cDNA inserts were subcloned into pSK+ (Stratagene) and sequenced from the 3' end. All 11 clones contained the same sequence, and th...