scholarly journals Substrate Specificities and Kinetic Parameters of Recombinant Drosophila melanogaster Glutathione S-Transferases E6 and E7

2018 ◽  
Author(s):  
Vennobaashini Venu ◽  
Zazali Alias
Keyword(s):  
Drosophila Melanogaster ◽  
Kinetic Parameters ◽  
Substrate Specificities ◽  
Glutathione S Transferases ◽  
E6 And E7

scholarly journals Isoelectric focusing of glutathione S-transferases from rat liver and kidney

1978 ◽  
Vol 175 (3) ◽  
pp. 937-943 ◽  
Author(s):  
Barbara F. Hales ◽  
Valerie Jaeger ◽  
Allen H. Neims
Keyword(s):  
Substrate Specificity ◽  
Isoelectric Focusing ◽  
Transferase Activity ◽  
Sprague Dawley ◽  
Substrate Specificities ◽  
Liver Cytosol ◽  
Sprague Dawley Rats ◽  
Isoelectric Points ◽  
Liver And Kidney ◽  
Glutathione S Transferases

The glutathione S-transferases that were purified to homogeneity from liver cytosol have overlapping but distinct substrate specificities and different isoelectric points. This report explores the possibility of using preparative electrofocusing to compare the composition of the transferases in liver and kidney cytosol. Hepatic cytosol from adult male Sprague–Dawley rats was resolved by isoelectric focusing on Sephadex columns into five peaks of transferase activity, each with characteristic substrate specificity. The first four peaks of transferase activity (in order of decreasing basicity) are identified as transferases AA, B, A and C respectively, on the basis of substrate specificity, but the fifth peak (pI6.6) does not correspond to a previously described transferase. Isoelectric focusing of renal cytosol resolves only three major peaks of transferase activity, each with narrow substrate specificity. In the kidney, peak 1 (pI9.0) has most of the activity toward 1-chloro-2,4-dinitrobenzene, peak 2 (pI8.5) toward p-nitrobenzyl chloride, and peak 3 (pI7.0) toward trans-4-phenylbut-3-en-2-one. Renal transferase peak 1 (pI9.0) appears to correspond to transferase B on the basis of pI, substrate specificity and antigenicity. Kidney transferase peaks 2 (pI8.5) and 3 (pI7.0) do not correspond to previously described glutathione S-transferases, although kidney transferase peak 3 is similar to the transferase peak 5 from focused hepatic cytosol. Transferases A and C were not found in kidney cytosol, and transferase AA was detected in only one out of six replicates. Thus it is important to recognize the contribution of individual transferases to total transferase activity in that each transferase may be regulated independently.

scholarly journals Human glutathione S-transferases. The Ha multigene family encodes products of different but overlapping substrate specificities.

1988 ◽  
Vol 263 (26) ◽  
pp. 12797-12800
Author(s):  
N W Chow ◽  
J Whang-Peng ◽  
C S Kao-Shan ◽  
M F Tam ◽  
H C Lai ◽  
...  
Keyword(s):  
Multigene Family ◽  
Substrate Specificities ◽  
Glutathione S Transferases

scholarly journals Purification and characterization of hepatic glutathione S-transferases of rhesus monkeys. A family of enzymes similar to the human hepatic glutathione S-transferases

1988 ◽  
Vol 251 (1) ◽  
pp. 81-88 ◽  
Author(s):  
R M Hoesch ◽  
T D Boyer
Keyword(s):  
Peroxidase Activity ◽  
Rhesus Monkeys ◽  
Affinity Column ◽  
Terminal Sequence ◽  
Glutathione S Transferase ◽  
Substrate Specificities ◽  
High Affinity ◽  
Human Enzyme ◽  
Hepatic Glutathione ◽  
Glutathione S Transferases

Thirteen forms of glutathione S-transferase were purified from the livers of female rhesus monkeys (Macaque mulatta). Most (74.7%) of the activity in the hepatic cytosol adhered well to the GSH affinity column and could be eluted only with the addition of GSH to the eluting buffer. The predominant isoenzymes (n = 5) in this ‘high-affinity’ fraction had alkaline pI values (greater than 9.0) and contained a subunit with an Mr value of 24,000. All of these isoenzymes had high organic peroxidase activity and, on the basis of amino acid analysis, substrate specificities and affinity for non-substrate ligands, appear to belong to the family of glutathione S-transferases that have been termed alpha [Mannervik, Alin, Guthenberg, Jensson, Tahir, Warholm & Jörnvall (1985) Proc. Natl. Acad. Sci. U.S.A. 82, 7202-7206]. Also within the high-affinity fraction was an isoenzyme with an acidic (5.8) pI value. This acidic isoenzyme was composed of a unique subunit (Mr 23,000). The N-terminal sequence (ten residues) of this acidic enzyme was identical with that of a human form that is referred to as pi. The predominant form of enzyme in the ‘low-affinity’ (eluted from the GSH affinity column with an increase in buffer pH) fraction was a homodimer of a 26,000-Mr subunit. It had an alkaline pI (greater than 9.0) but it lacked organic peroxidase activity. The N-terminal sequence (ten residues) of this enzyme was identical with that of a human enzyme referred to as mu. The substrate specificities and affinity for non-substrate ligands of this monkey enzyme also were similar to those of the human enzyme. In conclusion, the liver cytosol of rhesus monkeys contains a number of glutathione S-transferase isoenzymes that are very similar to the human hepatic enzymes.

scholarly journals Structure and function of one unclassified-class glutathione S-transferase in Leptinotarsa decemlineata

2021 ◽  
Author(s):  
Yanjun Liu ◽  
Timothy W Moural ◽  
Sonu BK Koirala ◽  
Jonathan Hernandez ◽  
Zhongjian Shen ◽  
...  
Keyword(s):  
Kinetic Parameters ◽  
Three Dimensional ◽  
Large Family ◽  
Dimensional Structure ◽  
Glutathione S Transferase ◽  
X Ray Crystallography ◽  
Xenobiotic Exposure ◽  
Multifunctional Enzymes ◽  
Glutathione S Transferases ◽  
And Function

Arthropod Glutathione S-transferases (GSTs) constitute a large family of multifunctional enzymes that are mainly associated with xenobiotic or stress adaptation. GST-mediated xenobiotic adaptation is through direct metabolism or sequestration of xenobiotics, and/or indirectly by providing protection against oxidative stress induced by xenobiotic exposure. To date, the roles of GSTs in xenobiotic adaptation in the Colorado potato beetle (CPB), a notorious agriculture pest of plants within Solanaceae have not been well studied. Here, we functionally expressed and characterized an unclassified-class GST, LdGSTu1. The three-dimensional structure of the LdGSTu1 was solved with a resolution up to 1.8 Å by x-ray crystallography. Recombinant LdGSTu1 was used to determine enzyme activity and kinetic parameters using 1-chloro-2,4-dinitrobenzene (CDNB), GSH, p-nitrophenyl acetate (PNA) as substrates. The enzyme kinetic parameters and enzyme-substrate interaction studies demonstrated that LdGSTu1 could catalyze the conjugation of GSH to both CDNB and PNA, with a higher turnover number for CDNB than PNA. The LdGSTu1 enzyme inhibition assays demonstrated that the enzymatic conjugation of GSH to CDNB could be inhibited by multiple pesticides, suggesting a potential function of LdGSTu1 in xenobiotic adaptation.

scholarly journals Biochemical Differences Between Alcohol Debydrogenases of Drosophila Melanogaster

1976 ◽  
Vol 29 (4) ◽  
pp. 365 ◽  
Author(s):  
JG Oakeshott
Keyword(s):  
Drosophila Melanogaster ◽  
The Other ◽  
Developmental Changes ◽  
Substrate Specificities ◽  
Ph Values ◽  
Ph Profiles

This paper describes substrate specificities, developmental changes in activity, pH profiles, and heat stabilities of isozymes produced by four Adh genotypes in D. melanogaster. No differences are found in the substrate specificities of isozymes from the different genotypes but studies of the other three properties reveal significant differences between the isozymes. Thus relatively low activities are found among extracts of AdhF Adhn2 larvae and among extracts of AdhF AdhF adults aged 44 days. Also AdhF Adhs and Adhs Adhs extracts have relatively high activities at pH 6� 5, and AdhF Adhn2 extracts have relatively low activities at pH values above 10�0. Finally, extracts of AdhF AdhF and AdhF Adhs are more stable at 40�C than are those of Adhs Adhs and AdhF Adhn2 ?

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