Electrophoretic patterns of γ-glutamyltransferase activity eluted from liver tissue

Echetebu, Z. O.; Moss, D. W.

doi:10.1016/0009-8981(79)90193-1

Cited by 9 publications

(5 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This procedure was repeated 4-6 times for each y-glutamyltransferase preparation. [6], Protein concentration was measured according to the method of Lowry et al [13], Treatment with Phospholipases C and A. y-Glutamyltransferase preparations (L, B3, Si, S2 and LS2) were incubated with 5 U/l phospholipase C for 24 h at 37 °C. Corresponding controls were incubated in the same way, but without added phospholipase.…”

Section: Methodsmentioning

confidence: 99%

Multiple Forms of Human γ-Glutamyltransferase

Echetebu¹,

Moss²

1982

Enzyme

View full text Add to dashboard Cite

Several forms of γ-glutamyltransferase have been prepared from human liver, bile and serum by size-dependent means, and have been subjected to digestions with trypsin, neuraminidase and phospholipases, extraction with deoxycholate and organic solvents, and freezing and thawing, to attempt to elucidate their nature and interrelationships. In general, these treatments alter the size and charge of the original fractions, producing in some cases resemblances between originally distinct fractions. All the forms appear to contain a catalytically active component of less than 20,000 molecular weight, which may be the small subunit of a common enzyme molecule. The observations are consistent with the view that multiple forms of γ-glutamyltransferase in human serum and bile arise by various modifications of a single type of enzyme.

show abstract

Section: Methodsmentioning

confidence: 99%

Multiple Forms of Human γ-Glutamyltransferase

Echetebu¹,

Moss²

1982

Enzyme

View full text Add to dashboard Cite

show abstract

“…Incubation of human liver tissue in a pool of sam ples of serum obtained from different patients or in non-protein solutions (9 g/1 NaCl and Ringer solution) was carried out at 37 °C as described previously [4].…”

Section: Methodsmentioning

confidence: 99%

“…incubation of human liver tissue in serum or protein-free solutions [4]. Some physico chemical and catalytic properties of the var ious enzyme forms have been determined.…”

Section: Introductionmentioning

confidence: 99%

“…However, the properties of the enzyme fractions which can be separated by these means and their relationship to each other and to tissue y-glutamyltransferase have not been extensively investigated. This paper describes the identification on the basis of molecular size of multiple forms of y-glutamyltransferase which occur natu rally in human liver, bile and serum, and of forms which can be obtained artificially by Many reports have appeared on the heter ogeneity of human y-glutamyltransferase (EC 2.3.2.2), particularly with regard to the elec trophoretic behaviour of the enzyme in se rum [1,4,8,11,16]. Rather fewer investiga tions have been made of the distribution of y-glutamyltransferase activity among molec ular forms of different sizes; nevertheless, considerable heterogeneity in this respect has of known molecular weight.…”

Section: Introductionmentioning

confidence: 99%

“…Electrophoresis in agarose gel (8 g/1 agarose in barbitone buffer of ionic strength 0.05, pH 8.6) and loca tion and scanning of zones of y-glutamyltransferase activity were carried out as previously described [4], y-Glutamyltransferase activity was determined by measurement of p-nitroaniline liberated during the enzyme-catalyzed transfer of glutamyl residues from T-y-glutamyl-p-nitroanilide to glycylglycine at 37 °C with the LKB Produkter AB 8600 Reaction Rate Analyzer equipped with 410-nm interference filters, under the conditions recommended by the Committee on Enzymes of the Scandinavian Society for Clinical Chemistry and Clinical Physiology [2].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Multiple Forms of Human y-Glutamyltransferase

Echetebu¹,

Moss²

1982

Enzyme

View full text Add to dashboard Cite

Eight fractions of human γ-glutamyltransferase were prepared from liver tissue, serum and bile by gel filtration. Bile, pooled serum from patients with high γ-glutamyltransferase activities and serum in which liver tissue had been incubated, each contained an enzyme fraction with molecular weight greater than 10^6. A fraction of about 80,000 molecular weight was obtained from bile, and by incubation of liver tissue in serum or sodium chloride solution, but not from the serum pool. The main enzyme fraction in native serum had a molecular weight of about 300,000, and the molecular weight of γ-glutamyltransferase partially purified from liver was initially 160,000. The fractions had similar K(m) and K(1) values, and differences in heat stability and binding to concanavalin A were not marked.

show abstract