Modular mutagenesis of exons 1, 2, and 8 of a glutathione S-transferase from the Mu class. Mechanistic and structural consequences for chimeras of isoenzyme 3-3

Zhang, Pinghui; Liu, Suxing; Shan, Shu‐ou; Ji, Xinhua; Gilliland, Gary L.; Armstrong, Richard N.

doi:10.1021/bi00157a005

Cited by 57 publications

(45 citation statements)

References 23 publications

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“…The K m of the high-affinity subunit of B1/B2 for GSH is one of the lowest values reported in the literature for either plant or mammalian GSTs. For mammalian GSTs an apparent K m for GSH of 27 m was reported for rat GST 4-4 with CDNB as a substrate (Zhang et al, 1992). A heterologously expressed GST from Arabidopsis exhibited an apparent K m of 80 m for GSH when assayed with CDNB (Bartling et al, 1993).…”

Section: Discussionmentioning

confidence: 99%

Isolation and Characterization of GlutathioneS-Transferase Isozymes from Sorghum1

1998

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Two glutathione S-transferase (GST) isozymes, A1/A1 and B1/B2, were purified from etiolated, O-1,3-dioxolan-2-yl-methyl-2,2,2,-trifluoro-4 -chloroacetophenone-oxime-treated sorghum (Sorghum bicolor L. Moench) shoots. GST A1/A1, a constitutively expressed homodimer, had a subunit molecular mass of 26 kD and an isoelectric point of 4.9. GST A1/A1 exhibited high activity with 1-chloro-2, 4,dinitrobenzene (CDNB) but low activity with the chloroacetanilide herbicide metolachlor. For GST A1/A1, the random, rapidequilibrium bireactant kinetic model provided a good description of the kinetic data for the substrates CDNB and glutathione (GSH). GST B1/B2 was a heterodimer with subunit molecular masses of 26 kD (designated the B1 subunit) and 28 kD (designated the B2 subunit) and a native isoelectric point of 4.8. GST B1/B2 exhibited low activity with CDNB and high activity with metolachlor as the substrate. The kinetics of GST B1/B2 activity with GSH and metolachlor fit a model describing a multisite enzyme having two binding sites with different affinities for these substrates. Both GST A1/A1 and GST B1/B2 exhibited GSH-conjugating activity with ethacrynic acid and GSH peroxidase activity with cumene hydroperoxide, 9-hydroperoxy-trans-10,cis-12-octadecadienoic acid and 13-hydroperoxy-cis-9,trans-11-octadecadienoic acid. Both GST A1/A1 and GST B1/B2 are glycoproteins, as indicated by their binding of concanavalin A. Polyclonal antibodies raised against GST A1/A1 exhibited cross-reactivity with the B1 subunit of GST B1/B2. Comparisons of the N-terminal amino acid sequences of the GST A1, B1, and B2 subunits with other type I -GSTs indicated a high degree of homology with the maize GST I subunit and a sugarcane GST.GSTs (EC 2.5.1.18) are dimeric enzymes found in mammals, insects, plants, and microbes that catalyze nucleophilic attack by the thiolate anion of GSH at electrophilic centers of hydrophobic molecules (Mannervik and Danielson, 1988). In addition to catalyzing GSH conjugation, GSTs also exhibit GSH peroxidase activity and ligandbinding functions (Mannervik and Danielson, 1988;Marrs, 1996). Mammalian GSTs compose a multigene family; in rat liver at least 13 different cytosolic GST subunits are found as either heterodimers or homodimers . Mammalian cytosolic GSTs have been divided into four classes (␣, , , and ) based on immunological, biochemical, and sequence similarities (Buetler and Eaton, 1992). It is well established that mammalian GSTs play an important role in the detoxification of electrophilic xenobiotics (Mannervik and Danielson, 1988). Although endogenous substrates for mammalian GSTs have not been clearly defined, there is evidence that ␣-GSTs protect against oxidative stress by detoxifying reactive products generated by lipid peroxidation (Ålin et al., 1985;Ketterer and Coles, 1991;Singhal et al., 1992).In general, plant GSTs have not been as well characterized as mammalian GSTs. Plant cytosolic GSTs belong to the archaic class of GSTs (Meyer et al., 1991;Marrs, 1996). This class, which is very heterog...

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Section: Discussionmentioning

confidence: 99%

Isolation and Characterization of GlutathioneS-Transferase Isozymes from Sorghum1

1998

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“…As a result, the potential carcinogens are eliminated, and DNA or other important biomolecules are protected against damage or adduct formation (Mannervik and Danielson, 1988;Zhang et al, 1992;Beckett and Hayes, 1993;Zhong et al, 1993;Ryberg et al, 1997). Glutathione S transferase-P1 (GSTP1) is a major GST, which is expressed in both normal and tumor of colon tissue (Singhal et al, 1992;Hoensch et al, 2006;Vlaykova et al, 2007).…”

Section: The Gstp1 Ile105val Polymorphism Is Not Associated With Suscmentioning

confidence: 99%

The GSTP1 Ile105Val Polymorphism is not Associated with Susceptibility to Colorectal Cancer

Khabaz

2012

Asian Pacific Journal of Cancer Prevention

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The glutathione S transferase (GST) family is a major part of cellular defense mechanisms against endogenous and exogenous substances, many of which have carcinogenic potential. Alteration in the expression level or structure of the glutathione-S-transferase (GST) enzymes may lead to inadequate detoxification of potential carcinogens and consequently contribute to cancer development. A member of the glutathione-S-transferase (GST) family, GSTP1, is an attractive candidate for involvement in susceptibility to carcinogen-associated colorectal cancer. An AgG transition in exon 5 resulting in an Ile105Val amino acid substitution has been identified which alters catalytic efficiency. The present study investigated the possible impact of Ile105Val GSTP1 polymorphism on susceptibility to colorectal cancer. in Jordan We examined 90 tissue samples previously diagnosed with colorectal carcinoma, and 56 non-cancerous colon tissues. DNA was extracted from paraffin embedded tissues and the status of the GSTP1 polymorphism was determined using a polymerase chain reaction restriction fragment length polymorphism (RFLP) method. No statistically significant differences were found between colorectal cancer cases and controls for the GSTP1 Ile/Ile, Ile/Val and Val/Val genotypes. The glutathione S-transferase polymorphism was not associated with risk in colorectal cancer cases in Jordan stratified by age, sex, site, grade or tumor stage. In conclusion, the GSTP1 Ile105Val polymorphism is unlikely to affect the risk of colorectal cancer.

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“…The presence of an aliphatic side chain at this position appears to be an important steric determinant for the stereoselective behaviour of class-mu-catalyzed addition reactions with a,p-unsaturated ketones and oxiranes [118]. In rGSTM2-2, a much more efficient and stereoselective catalyst than the rGSM1-1 isoenzyme towards these substrates, Val9 is replaced with the larger Ile side chain that would extend further into the Hsite.…”

Section: H-site and The Binding Of Electrophilesmentioning

confidence: 99%

X‐ray crystal structures of cytosolic glutathione S‐transferases

Dirr

Reinemer

Huber

1994

European Journal of Biochemistry

417

321

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Crystal structures of cytosolic glutathione S-transferases (EC 2.5.1.18), complexed with glutathione or its analogues, are reviewed. The atomic models define protein architectural relationships between the different gene classes in the superfamily, and reveal the molecular basis for substrate binding at the two adjacent subsites of the active site. Considerable progress has been made in understanding the mechanism whereby the thiol group of glutathione is destabilized (lowering its pK,) at the active site, a rate-enhancement strategy shared by the soluble glutathione S-transferases. Portrait of a superfamily of detoxification enzymesMany sophisticated defense strategies have evolved in organisms enabling them to deal with the constant threat by a broad spectrum of both foreign and endogenous cytotoxic and genotoxic compounds [1]. Enzyme systems that transact the chemical detoxification and elimination processes of these structurally diverse molecules, many of which are highly non-polar, can be divided into three major but interrelated groups; phase I enzymes, such as the cytochrome P450 superfamily, activate chemicals by forming reactive functional groups (e.g. epoxides) in them; phase I1 enzymes deactivate these reactive chemicals by appending a hydrophilic moiety (e.g. glutathionyl, glucuronyl, or sulphuryl) to the functional group ; phase Ill enzymes mediate the cellular elimination of the inactive and water-soluble products.The superfamily of glutathione S-transferases (EC 2.5.1.18) represents an integral part of the phase I1 detoxification mechanism. These intracellular proteins are found in most aerobic eukaryotes and prokaryotes, and protect cells against chemical-induced toxicity and stress by catalyzing the S-conjugation between the thiol group of glutathione and an electrophilic moiety in the hydrophobic and toxic sub- GST, glutathione S-transferase; pGSTP1-1, hGSTAl-1, rGSTM1-1 etc., acronyms for the glutathione S-transferases (GST), the prefix indicating the species (p, porcine; h, human ; r, rat; b, bovine; m, mouse; rb, rabbit; c, chicken; gp, guinea pig) while P, A, and M indicate gene class pi, alpha and mu, respectively ; 1-1 indicates a dimer of two type-1 subunits; GSH, reduced glutathione; P1, P2 etc. and G1, G2 etc., designate peptide functional groups in glutathione and the corresponding G-site ligands of the glutathione S-transferases, respectively; G-site, glutatbione-binding site; H-site, hydrophobic electrophile-binding site.Enzyme. Glutathione S-transferase (EC 2.5.1.1 8).strate. Glutathione S-transferases are perhaps the single most important family of enzymes involved in the metabolism of alkylating compounds [2]. The resultant glutathione S-conjugates can be exported from animal cells by putative membrane ATP-dependent pump systems [3] after which they are metabolized via the mercapturate pathway and eventually eliminated. An extraordinary feature of the glutathione S-transferase superfamily is the occurrence of multiple enzyme forms that, according to sequence similarities and subc...

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Modular mutagenesis of exons 1, 2, and 8 of a glutathione S-transferase from the Mu class. Mechanistic and structural consequences for chimeras of isoenzyme 3-3

Cited by 57 publications

References 23 publications

Isolation and Characterization of GlutathioneS-Transferase Isozymes from Sorghum1

Isolation and Characterization of GlutathioneS-Transferase Isozymes from Sorghum1

The GSTP1 Ile105Val Polymorphism is not Associated with Susceptibility to Colorectal Cancer

X‐ray crystal structures of cytosolic glutathione S‐transferases

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