The Gardner 6C3HED lymphosarcoma, Leukemia L-1210, and Leukemia L-1210/aza in ascites form were inhibited in in vivo experiments by a highly purified preparation of glutaminase-asparaginase from a pseudomonad. The glutamine con tent of tumors was measured by an enzymatic micromethod. The results showed that glutaminase-treated tumors were depleted of free glutamine. The glutamine-synthetase act...

An L-glutaminase producing microorganism was isolated and identified as Bacillus subtilis RSP-GLU. The production pattern of the enzyme by isolated microorganism was studied in submerged fermentations (Smf). Initially various process parameters such as pH, incubation temperature, inoculum concentration and agitation speed were optimized based on the one-at-a-time method. It was noticed that at ...

Protein ageing is often mediated by the formation of succinimide intermediates. These short-lived intermediates derive from asparaginyl deamidation and aspartyl dehydration and are rapidly converted into β-aspartyl or D-aspartyl residues. Here we report the presence of a highly stable succinimide intermediate in the glutaminase subunit of GMP synthetase from the hyperthermophile Methanocaldocco...

Glutaminase (GLS) isoenzymes GLS1 and GLS2 are key enzymes for glutamine metabolism. Interestingly, GLS1 and GLS2 display contrasting functions in tumorigenesis with elusive mechanism; GLS1 promotes tumorigenesis, whereas GLS2 exhibits a tumor-suppressive function. In this study, we found that GLS2 but not GLS1 binds to small GTPase Rac1 and inhibits its interaction with Rac1 activators guanine...

Cancer cells reprogram metabolism to provide the energy, nucleotides, lipids, amino acids and other building blocks required to proliferate and survive in the stressful tumor microenvironment [1]. Changes in cancer metabolism were first noted in the 1920’s with Otto Warburg’s discovery that tumors show increased aerobic conversion of glucose to lactate (termed the Warburg Effect). A recent revi...

A method for preparing highly purified glutaminase (EC 3.5.1.2, L-glutamine amidohydrolase) from pig renal cortex is described. The main steps consist of sodium sulfate fractionation followed by alternative solubilization by dialysis against Tris-HCI buffer and precipitation with phosphateborate. The linal enzyme preparation contains no impurities which could be detected by sucrose gradient cen...

Protein allosteric pathways are investigated in the imidazole glycerol phosphate synthase heterodimer in an effort to elucidate how the effector (PRFAR, N'-[(5'-phosphoribulosyl)formimino]-5-aminoimidazole-4-carboxamide ribonucleotide) activates glutaminase catalysis at a distance of 25 Å from the glutamine-binding site. We apply solution NMR techniques and community analysis of dynamical netwo...

In a mixture containing γ-glutamyl donor (donor) and γ-glutamyl acceptor (acceptor), the glutaminase of Pseudomonas nitroreducens IFO 12694 simultaneously catalyzed a γ-glutamyl transfer reaction and hydrolysis of the donor. The variation of the activities responding to the concentration of glutathione and glycylglycine indicated that the enzyme might be classified in a group of glutaminases th...