A new method for the assay of glutaminase activity: Direct measurement of product formation by an ammonia electrode

Huang, Yeh-Zen

doi:10.1016/0003-2697(74)90413-8

Cited by 21 publications

(6 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For measurement of urinary ammonia, samples were thawed, diluted with double-distilled water and mixed with an equal volume of 8 % perchloric on ice. Each sample was then alkalinized with an excess of 10 A NaOH and ammonia concentration was measured in duplicate with an Orion model 95-10 ammonia electrode [13]. Severely ill infants were excluded from the study.…”

Section: Methodsmentioning

confidence: 99%

Antenatal Betamethasone and Renal Ammoniagenesis in the Newborn

Goodyer¹,

Lazaro-Lopez²,

Papageorgiou³

1981

Dev Pharmacol Ther

View full text Add to dashboard Cite

As part of a double-blind clinical trial of antenatal betamethasone, we studied the effects of this drug on urinary ammonia excretion in 28 premature infants. Betamethasone was administered before 34 weeks of gestation according to dosage schedules which have been shown to alter the incidence of respiratory distress syndrome. Although glucocorticoids affect renal ammoniagenesis in adults, the antenatal betamethasone trial did not augment ammonia excretion measured during the first day of postnatal life. We speculate that precocious maturation of renal ammoniagenesis cannot be triggered by glucocorticoids during the gestational period studied.

show abstract

Section: Methodsmentioning

confidence: 99%

Antenatal Betamethasone and Renal Ammoniagenesis in the Newborn

Goodyer¹,

Lazaro-Lopez²,

Papageorgiou³

1981

Dev Pharmacol Ther

View full text Add to dashboard Cite

show abstract

“…The three glutaminase reactions described here were all defined by their yield of stoichiometric amounts of NH3 and glutamate [ [10]. While there could in principle still be confusion between a glutaminase and the reversed reaction of glutamine synthetase, which would also give glutamate and NH3, the properties, distribution and activity of the latter enzyme in rat tissues are not confusable with a glutaminase [8,9].…”

Section: Discussionmentioning

confidence: 99%

“…Since this blank reaction forms NH3 and pyrrolidone-5-carboxylate instead of glutamate [10], the measurement of glutamate formation offers a more specific and sensitive assay [4] for use when large and active samples like those used here are not available.…”

Section: Discussionmentioning

confidence: 99%

A Comparative Study of Glutaminase Isozymes in Rat Tissues

Huang

We²

1976

Enzyme

Self Cite

View full text Add to dashboard Cite

The three kinds of glutaminases in rat kidney and liver were defined in comparative terms by their properties and were separately purified. Substantial purification was obtained by polymerization and depolymerization of the kidney isozyme that is activated by phosphate. These isozymes differ most strikingly in the activators of their reactions : maleate and a high concentration of phosphate, respectively, for the two kidney isozymes, and a low concentration of phosphate for the liver isozyme. The kidney isozyme that is activated by phosphate was also activated by a much lower concentration of ATP and by other complex phosphates. They also differ in physical properties : the maleate-activated isozyme was heat resistant (50°C) and associated with insoluble submitochondrial particles; both phosphateactivated isozymes were heat sensitive and could be solubilized from their respective mitochondria; the phosphate-activated isozyme of kidney polymerized in phosphate-borate solution while that of liver did not. The characteristics of the kidney isozyme that was activated by high phosphate were shared by the glutaminases in adult brain, transplanted tumors, and in fetal liver and kidney. The similarity to the kidney enzyme was confirmed by the use of polymerization in phosphate borate of the isozyme from a mammary carcinoma to effect its purification.

show abstract

“…Ushijima and Nakadai 116 used mutation and protoplast fusion techniques for improving LGlutaminase production by A. sojae employed in shoyu fermentation. Mulchandani and Bassi, 17,117,118,119,120 and hybridoma culture media 121 by flow injection analysis.…”

Section: Application Of L-glutaminase In Food Industrymentioning

confidence: 99%

“…The enzyme has also been widely employed in the monitoring of glutamine and glutamate levels in mammalian cell culture media 119,120 and hybridoma culture media 121 by flow injection analysis using biosensors. Free enzyme was used in the determination of glutamine in insect cell culture media by Wang et al 122 .…”

Section: Application Of L-glutaminase In Food Industrymentioning

confidence: 99%

Untitled

2014

IJPSR

View full text Add to dashboard Cite

ABSTRACT:One of the prime candidates in the treatment of debilitating human cancers includes a family of enzymes referred to as L-glutaminases. The antitumor activity of these enzymes found effective in countering Acute Lymphoblastic Leukemia (ALL a commonly diagnosed pediatric cancer.). .Apart from therapeutic use, it is having a number of other applications like in food industry, analysis and in production of fine chemicals. This review, hence, mainly focuses on the biochemical aspects of L-Glutaminase production, aiming to comprehend the physiochemical characteristics, application of LGlutaminase and its properties. Processes central to these biochemical aspects, including submerged fermentation and Solid state fermentation of Lglutaminase producing organisms are also discussed.

show abstract

A new method for the assay of glutaminase activity: Direct measurement of product formation by an ammonia electrode

Cited by 21 publications

References 7 publications

Antenatal Betamethasone and Renal Ammoniagenesis in the Newborn

Antenatal Betamethasone and Renal Ammoniagenesis in the Newborn

A Comparative Study of Glutaminase Isozymes in Rat Tissues

Untitled

Contact Info

Product

Resources

About