Bio-nanogate involves synthesized or natural molecules as a 'gate' towards bioreceptors and responds upon the presence of targeted analytes in nanoscale dimension. Development of bio-nanogate improves analyte selectivity and signal response across various types of biosensors. The versatility of PAMAM dendrimers to form conjugates with guest molecules, such as proteins can be utilized in forming a bio-nanogate. PAMAM interaction with peptide bioreceptor for antibody detection is of interest in this study. This study investigated the interaction of synthesized immunogenic 'a' determinant (aD) region of hepatitis B virus surface antigen (HBsAg) with PAMAM G4 and anti-HBsAg antibody, as a potential bio-nanogate for anti-HBsAg detection. The aD peptide fused with maltose binding protein (MBP), was confirmed with Western blotting. Nano-Differential Scanning Fluorimetry (nano-DSF) study revealed that the interaction of MBP-aD with anti-HBsAg indicated a higher thermal stability as compared to its interaction with PAMAM G4. Electrochemical impedance spectroscopy showed that a higher binding constant of MBP-aD interaction with anti-HBsAg (0.92 μM-1) was observed at maximum saturation, as compared with PAMAM G4 (0.07 μM-1). Thermodynamic parameters demonstrated that MBP-aD interacted with anti-HBsAg and PAMAM G4, through van der Waals and hydrogen bonding. These analyses suggest that the weak interaction of MBP-aD and PAMAM G4 may form a potential bio-nanogate. It is hypothesized that the presence of anti-HBsAg has a higher affinity towards MBP-aD which may displace PAMAM G4 in the anti-HBsAg detection system. This interaction study is crucial as an initial platform of using peptide-PAMAM as a bio-nanogate in an antibody detection system.
Two Infectious bursal disease virus (IBDV) isolates, NP1SSH and NP2K were obtained from a severe infectious bursal disease (IBD) outbreak in Nepal in 2002. The hypervariable (HV) region of VP2 gene (1326 bp) of the isolates was generated by RT-PCR and sequenced. The obtained nucleotide sequences were compared with those of twenty other IBDV isolates/strains. Phylogenetic analysis based on this comparison revealed that NP1SSH and NP2K clustered with very virulent (vv) IBDV strains of serotype 1. In contrast, classical, Australian classical and attenuated strains of serotype 1 and avirulent IBDV strains of serotype 2 formed a different cluster. The deduced amino acid sequences of the two isolates showed a 98.3% identity with each other and 97.1% and 98.3% identities, respectively with very virulent IBDV (vvIBDV) isolates/strains. Three amino acids substitutions at positions 300 (E-->A), 308 (I-->F) and 334 (A-->P) within the HV region were common for both the isolates. The amino acids substitutions at positions 27 (S-->T), 28 (I-->T), 31 (D-->A), 36 (H-->Y), 135 (E-->G), 223 (G-->S), 225 (V-->I), 351 (L-->I), 352 (V-->E) and 399 (I-->S) for NP1SSH and at position 438 (I-->S) for NP2K were unique and differed from other IBDV isolates/strains. NP1SSH and NP2K showed highest similarity (97.8%) with the BD399 strain from Bangladesh as compared with other vvIBDV isolates/strains. We conclude that the NP1SSH and NP2K isolates of IBDV from Nepal represent vvIBDV of serotype 1.
The complete nucleotide sequences encoding precursor polyprotein (VP2-VP3-VP4) and VP5 of a highly virulent (hv) infectious bursal disease virus (IBDV), UPM97/61 was determined. Comparison of the deduced amino acid sequences with the published ones revealed 8 common amino acid substitutions, which were found only in the hv IBDV including the UPM97/61 strain. Three of the amino acid substitutions (222 Ala, 256 Ile and 294 Ile) were used as a marker for determining hv IBDV strains. The other five substitutions (685 Asn, 715 Ser, 751 Asp, 990 Val and 1005 Ala) were also conserved in hv IBDV strains isolated in various countries. UPM97/61 strain demonstrated also 8 unique amino acid substitutions of which 3 were in VP2, 4 in VP3 and 1 in VP4. There was 1 unique amino acid substitution in VP5 at position 19 (Asp-->Gly) not found in other strains. However, all the strains have a conserved 49 Arg. The amino acid sequence of UPM97/61 strain differed by 1.09% from the Japanese (OKYM) and Hong Kong (HK46) strains, and by 1.48% from the Israeli (IBDVKS) and European (UK661) strains. Hence, UPM97/61 is more closely related to the hv strains from Asia. However, phylogenetic analysis indicated that the origin of UPM97/61 might be the same as that of other hv strains isolated from other parts of the world.
Previously we have shown that very virulent infectious bursal disease viruses (vvIBDV) that are SspI, TaqI and StyI positive (92/04, 97/61 and 94/B551) but not SspI and TaqI positive and StyI negative (94/273) cause high mortality, up to 80% in specific-pathogen-free chickens with significant damage of the bursal as well as nonbursal tissues. In this study, we sequenced the VP2 gene (1351 bp) of the 92/04, 94/273 and 94/B551 and compared them with other IBDV strains. All the isolates have the unique amino acid residues at positions 222A, 256I, 294I and 299S found in other vvIBDV strains. The deduced VP2 amino acids encoded by 92/04 is identical to the vvIBDV strains from Israel (IBDVKS), Japan (OKYM) and Europe (UK661), whereas the 94/273 and 94/B551 isolates have one to three amino acid substitutions. The 94/273 has two amino acid substitutions at positions 254 G to S and at 270 A to E that have not been reported before from vvIBDV strains. The 94/B551 also has one amino acid substitution at position 300 E to S, which is uncommon among other vvIBDV strains. However, phylogenetic analysis suggested that the isolates are very close to each other and all of them may have derived from the same origin as vvIBDV strains isolated from China, Japan and Europe. Even though antigenic index analysis of the 94/273 and 94/B551 indicated that the isolates are unique compared to other IBDV strains, their antigenic variation remain to be determined by monoclonal antibody study.
The VP2 hypervariable region of P97/302 local infectious bursal disease virus (IBDV) isolate was amplified by the reverse transcriptase (RT) nested polymerase chain reaction (PCR) and cloned. This region of P97/302 local isolate was sequenced and compared with eight other reported IBDV sequences. The result showed that P97/302 IBDV was most identical to the reported very virulent IBDV strains because it has amino acid substitutions at positions 222, 256, 294, and 299, which encode alanine, isoleucine, isoleucine, and serine, respectively. This region can be digested with restriction enzymes of Taq1, Sty1, Ssp1 but not with Sac1. The P97/302 isolate was then used for the optimization of RT nested PCR enzyme-linked immunosorbent assay (ELISA). The RT nested PCR ELISA was able to detect 10(-4) dilution of the infected bursa homogenates and was 10 times more sensitive when compared with the agarose gel detection method. The RT nested PCR ELISA can detect up to 0.48 ng of the PCR product. The specificity of this nested PCR ELISA was also high (100%).
The expressed sequence tag (EST) effort in Toxoplasma gondii has generated a substantial amount of gene information. To exploit this valuable resource, we chose to study tgd057, a novel gene identified by a large number of ESTs that otherwise show no significant match to known sequences in the database. Northern analysis showed that tgd057 is transcribed in this tachyzoite. The complete cDNA sequence of tgd057 is 1169 bp in length. Sequence analysis revealed that tgd057 possibly adopts two polyadenylation sites, utilizes the fourth in-frame ATG for translation initiation, and codes for a secretory protein. The longest open reading frame for the tgd057 gene was cloned and expressed as a recombinant protein (rd57) in Escherichia coli. Western analysis revealed that serum against rd57 recognized a molecule of ~21 kDa in the tachyzoite protein extract. This suggests that the tgd057 gene is expressed in vivo in the parasite.
GalNAc-T1, a key candidate of GalNac-transferases genes family that is involved in mucin-type O-linked glycosylation pathway, is expressed in most biological tissues and cell types. Despite the reported association of GalNAc-T1 gene mutations with human disease susceptibility, the comprehensive computational analysis of coding, noncoding and regulatory SNPs, and their functional impacts on protein level, still remains unknown. Therefore, sequence- and structure-based computational tools were employed to screen the entire listed coding SNPs of GalNAc-T1 gene in order to identify and characterize them. Our concordant in silico analysis by SIFT, PolyPhen-2, PANTHER-cSNP, and SNPeffect tools, identified the potential nsSNPs (S143P, G258V, and Y414D variants) from 18 nsSNPs of GalNAc-T1. Additionally, 2 regulatory SNPs (rs72964406 and #x26; rs34304568) were also identified in GalNAc-T1 by using FastSNP tool. Using multiple computational approaches, we have systematically classified the functional mutations in regulatory and coding regions that can modify expression and function of GalNAc-T1 enzyme. These genetic variants can further assist in better understanding the wide range of disease susceptibility associated with the mucin-based cell signalling and pathogenic binding, and may help to develop novel therapeutic elements for associated diseases.
Survivin is an inhibitor of apoptosis protein and regulates the cell cycle in the G2/M phase. Survivin is expressed during embryonic and fetal development, selectively over-expressed in common human cancers and completely down-regulated in normal adult tissue. This work was aimed at studying the expression of the survivin homologues and their subcellular distribution in fetal and normal adult tissues of rat. Survivin expression was evaluated by immunohistochemistry in formalin-fixed, paraffin-embedded tissue sections of fetal and normal adult tissues of rat using the polyclonal serum SUR12A-CFI. This serum demonstrated intense positive survivin staining in adult kidney, ovary and oviduct, and a variable expression in different fetal organs, with particularly intense expression detected in the adrenal gland, liver, stomach, small intestine, colon, kidney and skin. In both fetal and adult tissues, the expression was predominantly cytoplasmic. It was concluded that survivin was abundantly and prominently expressed during fetal development in rat and that the polyclonal anti-human survivin antibody SUR12A-CFI is reactive with rat survivin.
Abscisic acid (ABA) is an important phytohormone involved in the abiotic stress resistance in plants. The ABA-responsive element (ABRE) binding factors play significant roles in the plant development and response to abiotic stresses, but none so far have been isolated and characterized from the oil palm. Two ABA-responsive cDNA clones, named EABF and EABF1, were isolated from the oil palm fruits using yeast one-hybrid system. The EABF had a conserved AP2/EREBP DNA-binding domain (DNA-BD) and a potential nuclear localization sequence (NLS). No previously known DNA-BD was identified from the EABF1 sequence. The EABF and EABF1 proteins were classified as DREB/CBF and bZIP family members based on the multiple sequence alignment and phylogenetic analysis. Both proteins showed ABRE-binding and transcriptional activation properties in yeast. Furthermore, both proteins were able to trans-activate the down-stream expression of the LacZ reporter gene in yeast. An electrophoretic mobility shift assay revealed that in addition to the ABRE sequence, both proteins could bind to the DRE sequence as well. Transcriptional analysis revealed that the expression of EABF was induced in response to the ABA in the oil palm fruits and leaves, but not in roots, while the EABF1 was constitutively induced in all tissues. The expressions of both genes were strongly induced in fruits in response to the ABA, ethylene, methyl jasmonate, drought, cold and high-salinity treatments, indicating that the EABF and EABF1 might act as connectors among different stress signal transduction pathways. Our results indicate that the EABF and EABF1 are novel stress-responsive transcription factors, which are involved in the abiotic stress response and ABA signaling in the oil palm and could be used for production of stress-tolerant transgenic crops.
A truncated haemoglobin (tHb) has been identified in an acidophilic and thermophilic methanotroph Methylacidiphilium infernorum. Hell's Gate Globin IV (HGbIV) and its related tHbs differ from all other bacterial tHbs due to their distinctively large sequence and polar distal haem pocket residues. Here we report the crystal structure of HGbIV determined at 1.96 Å resolution. The HGbIV structure has the distinctive 2/2 α-helical structure with extensions at both termini. It has a large distal site cavity in the haem pocket surrounded by four polar residues: His70(B9), His71(B10), Ser97(E11) and Trp137(G8). This cavity can bind bulky ligands such as a phosphate ion. Conformational shifts of His71(B10), Leu90(E4) and Leu93(E7) can also provide more space to accommodate larger ligands than the phosphate ion. The entrance/exit of such bulky ligands might be facilitated by positional flexibility in the CD1 loop, E helix and haem-propionate A. Therefore, the large cavity in HGbIV with polar His70(B9) and His71(B10), in contrast to the distal sites of other bacterial tHbs surrounded by non-polar residues, suggests its distinct physiological functions.
A truncated form of an α-amylase, GTA, from thermophilic Geobacillus thermoleovorans CCB_US3_UF5 was biochemically and structurally characterized. The recombinant GTA, which lacked both the N- and C-terminal transmembrane regions, functioned optimally at 70°C and pH 6.0. While enzyme activity was not enhanced by the addition of CaCl2, GTA's thermostability was significantly improved in the presence of CaCl2. The structure, in complex with an acarbose-derived pseudo-hexasaccharide, consists of the typical three domains and binds one Ca(2+) ion. This Ca(2+) ion was strongly bound and not chelated by EDTA. A predicted second Ca(2+)-binding site, however, was disordered. With limited subsites, two novel substrate-binding residues, Y147 and Y182, may help increase substrate affinity. No distinct starch-binding domain is present, although two regions rich in aromatic residues have been observed. GTA, with a smaller domain B and several shorter loops compared to other α-amylases, has one of the most compact α-amylase folds that may contribute greatly to its tight Ca(2+) binding and thermostability.
beta-Galactosidase (EC. 3.2.1.23) from ripe carambola (Averrhoa carambola L. cv. B10) fruit was fractionated through a combination of ion exchange and gel filtration chromatography into four isoforms, viz. beta-galactosidase I, II, III and IV. This beta-galactosidases had apparent native molecular masses of 84, 77, 58 and 130 kDa, respectively. beta-Galactosidase I, the predominant isoform, was purified to electrophoretic homogeneity; analysis of the protein by SDS-PAGE revealed two subunits with molecular masses of 48 and 36 kDa. N-terminal amino acid sequence of the respective polypeptides shared high similarities albeit at different domains, with the deduced amino acid sequence of certain plant beta-galactosidases, thus, explaining the observed low similarity between the two subunits. beta-Galactosidase I was probably a heterodimer that have glycoprotein properties and a pI value of 7.2, with one of the potential glycosylation sites appeared to reside within the 48-kDa-polypeptide. The purified beta-galactosidase I was substantially active in hydrolyzing (1-->4)beta-linked spruce and a mixture of (1-->3)beta- and (1-->6)beta-linked gum arabic galactans. This isoform also had the capability to solubilize and depolymerize structurally intact pectins as well as to modify alkaline-soluble hemicelluloses, reflecting in part changes that occur during ripening.
Glutathione transferases (GST) were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW) of 23 kDa. 2-dimensional (2-D) gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5) and GST2 (pI 6.2) with identical MW. GST1 was reactive towards ethacrynic acid, hydrogen peroxide, 1-chloro-2,4-dinitrobenzene, and trans,trans-hepta-2,4-dienal while GST2 was active towards all substrates except hydrogen peroxide. This demonstrated that GST1 possessed peroxidase activity which was absent in GST2. This study also showed that only GST2 was able to conjugate GSH to isoproturon, a herbicide. GST1 and GST2 were suggested to be similar to F0KLY9 (putative glutathione S-transferase) and F0KKB0 (glutathione S-transferase III) of Acinetobacter calcoaceticus strain PHEA-2, respectively.
Drosophila melanogaster glutathione S-transferase D3 (DmGSTD3) has a shorter amino acid sequence as compared to other GSTs known in the fruit flies. This is due to the 15 amino acid N-terminal truncation in which normally active amino acid residue is located. The work has made use of homology modeling to visualize the arrangement of amino acid side chains in the glutathione (GSH) substrate cavity. The identified amino acids were then replaced with amino acids without functional groups in the side chains and the mutants were analyzed kinetically. Homology modeling revealed that the side chains of Y89 and Y97 were shown facing toward the substrate cavity proposing their possible role in catalyzing the conjugation. Y97A and Y89A GSH gave large changes in Km (twofold increase), Vmax (fivefold reduction), and Kcat /Km values for GSH suggesting their significant role in the conjugation reaction. The replacement at either positions has not affected the affinity of the enzyme toward 1-chloro-2,4-dinitrobenzene as no significant change in values of Kmax was observed. The replacement, however, had significantly reduced the catalytic efficiency of both mutants with (Kcat /Km )(GSH) and (Kcat /Km )(CDNB) of eight- and twofold reduction. The recombinant DmGSTD3 has shown no activity toward 1,2-dichloro-4-nitrobenzene, 2,4-hexadienal, 2,4-heptadienal, p-nitrobenzyl chloride, ethacrynic acid, and sulfobromophthalein. Therefore, it was evident that DmGSTD3 has made use of distal amino acids Y97 and Y89 for GSH conjugation.
Angiotensin I-converting enzyme (ACE) inhibitors derived from foods are valuable auxiliaries to agents such as captopril. Eight highly functional ACE inhibitory peptides from the mushroom, Agaricus bisporus, were identified by LC-MS/MS. Among these peptides, the most potent ACE inhibitory activity was exhibited by AHEPVK, RIGLF and PSSNK with IC₅₀ values of 63, 116 and 129 μM, respectively. These peptides exhibited high ACE inhibitory activity after gastrointestinal digestion. Lineweaver-Burk plots suggested that AHEPVK and RIGLF act as competitive inhibitors against ACE, whereas PSSNK acts as a non-competitive inhibitor. Mushrooms can be a good component of dietary supplement due to their readily available source and, in addition, they rarely cause food allergy. Compared to ACE inhibitory peptides isolated from other edible mushrooms, AHEPVK, RIGLF and PSSNK have lower IC₅₀ values. Therefore, these peptides may serve as an ideal ingredient in the production of antihypertensive supplements.
The monkey malaria parasite Plasmodium knowlesi is now recognized as the fifth species of Plasmodium that can cause human malaria. Like the region II of the Duffy binding protein of P. vivax (PvDBPII), the region II of the P. knowlesi Duffy binding protein (PkDBPαII) plays an essential role in the parasite's invasion into the host's erythrocyte. Numerous polymorphism studies have been carried out on PvDBPII, but none has been reported on PkDBPαII. In this study, the genetic diversity, haplotyes and allele groups of PkDBPαII of P. knowlesi clinical isolates from Peninsular Malaysia were investigated.
This study investigates the complete molecular characterization including bioinformatics characterization, gene expression, synthesis of N and C terminal peptides and their antimicrobial activity of the core histone 4 (H4) from freshwater giant prawn Macrobrachium rosenbergii (Mr). A cDNA encoding MrH4 was identified from the constructed cDNA library of M. rosenbergii during screening and the sequence was obtained using internal sequencing primers. The MrH4 coding region possesses a polypeptide of 103 amino acids with a calculated molecular weight of 11kDa and an isoelectric point of 11.5. The bioinformatics analysis showed that the MrH4 polypeptide contains a H4 signature at (15)GAKRH(19). Multiple sequence alignment of MrH4 showed that the N-terminal (21-42) and C-terminal (87-101) antimicrobial peptide regions and the pentapeptide or H4 signature (15-19) are highly conserved including in humans. The phylogenetic tree formed two separate clades of vertebrate and invertebrate H4, wherein MrH4 was located within the arthropod monophyletic clade of invertebrate H4 groups. Three-dimensional model of MrH4 was established using I-TASSER program and the model was validated using Ramachandran plot analysis. Schiffer-Edmundson helical wheel modeling was used to predict the helix propensity of N (21-42) and C (87-101) terminal derived Mr peptides. The highest gene expression was observed in gills and is induced by viral [white spot syndrome baculovirus (WSBV) and M. rosenbergii nodovirus (MrNV)] and bacterial (Aeromonas hydrophila and Vibrio harveyi) infections. The N and C terminal peptides were synthesized and their antimicrobial and hemolytic properties were examined. Both peptides showed activity against the tested Gram negative and Gram positive bacteria; however, the highest activity was noticed against Gram negative bacteria. Among the two peptides used in this study, C-terminal peptide yielded better results than the N-terminal peptide. Therefore, C terminal peptide can be recommended for the development of an antimicrobial agent.
CXCR3 is a CXC chemokine receptor 3 which binds to CXC ligand 4 (CXCL4), 9, 10 and 11. CXC chemokine receptor 3a (CXCR3a) is one of the splice variants of CXCR3. It plays crucial role in defense and other physiological processes. In this study, we report the molecular cloning, characterization and gene expression of CXCR3a from striped murrel Channa striatus (Cs). The full length CsCXCR3a cDNA sequence was obtained from the constructed cDNA library of striped murrel by cloning and sequencing using an internal sequencing primer. The full length sequence is 1425 nucleotides in length including an open reading frame of 1086 nucleotides which is encoded with a polypeptide of 361 amino acids (mol. wt. 40 kDa). CsCXCR3a domain analysis showed that the protein contains a G protein coupled receptor between 55 and 305 along with its family signature at 129-145. The transmembrane prediction analysis showed that CsCXCR3a protein contains 7 transmembrane helical regions at 34-65, 80-106, 113-146, 154-181, 208-242, 249-278 and 284-308. The 'DRY' motif from CsCXCR3a protein sequence at (140)Asp-(141)Arg-(142)Tyr which is responsible for G-protein binding is also highly conserved with CXCR3 from other species. Phylogenetic tree showed that the CXC chemokine receptors 3, 4, 5 and 6, each formed a separate clade, but 1 and 2 were clustered together, which may be due to the high similarity between these receptors. The predicted 3D structure revealed cysteine residues, which are responsible for 'CXC' motif at 116 and 198. The CsCXR3a transcript was found to be high in kidney, further its expression was up-regulated by sodium nitrite acute toxicity exposure, fungal, bacterial and poly I:C challenges. Overall, these results supported the active involvement of CsCXCR3a in inflammatory process of striped murrel during infection. However, further study is necessary to explore the striped murrel chemokine signaling pathways and their roles in defense system.
In this study, we reported a molecular characterization of a novel proto-type galectin-1 from the striped murrel Channa striatus (named as CsGal-1). The full length CsGal-1 was identified from an established striped murrel cDNA library and further we confirmed the sequence by cloning. The complete cDNA sequence of CsGal-1 is 590 base pairs (bp) in length and its coding region encoded a poly peptide of 135 amino acids. The polypeptide contains a galactoside binding lectin domain at 4-135. The domain carries a sugar binding site at 45-74 along with its signatures (H(45)-X-Asn(47)-X-Arg(49) and Trp(69)-X-X-Glu(72)-X-Arg(74)). CsGal-1 shares a highly conserved carbohydrate recognition domain (CRD) with galectin-1 from other proto-type galectin of teleosts. The mRNA expressions of CsGal-1 in healthy and various immune stimulants including Aphanomyces invadans, Aeromonas hydrophila, Escherchia coli lipopolysaccharide and poly I:C injected tissues of C. striatus were examined using qRT-PCR. CsGal-1 mRNA is highly expressed in kidney and is up-regulated with different immune stimulants at various time points. To understand its biological activity, the coding region of CsGal-1 gene was expressed in an E. coli BL21 (DE3) cloning system and its recombinant protein was purified. The recombinant CsGal-1 protein was agglutinated with mouse erythrocytes at a concentration of 4μg/mL in a calcium independent manner. CsGal-1 activity was inhibited by d-galactose at 25mM(-1) and d-glucose and d-fructose at 100mM(-1). The results of microbial binding assay showed that the recombinant CsGal-1 protein agglutinated only with the Gram-negative bacteria. Interestingly, we observed no agglutination against Gram-positive bacteria. Overall, the study showed that CsGal-1 is an important immune gene involved in the recognition and elimination of pathogens in C. striatus.
This study reports the comprehensive comparative information of two different detoxification enzymes such as glutathione S-transferases (GSTs) delta and kappa from freshwater giant prawn Macrobrachium rosenbergii (designated as MrGSTD and MrGSTK) by investigating their in-silico characters and mRNA modulation against various biotic and abiotic oxidative stressors. The physico-chemical properties of these cDNA and their polypeptide structure were analyzed using various bioinformatics program. The analysis indicated the variation in size of the polypeptides, presence or absence of domains and motifs and structure. Homology and phylogenetic analysis revealed that MrGSTD shared maximum identity (83%) with crustaceans GST delta, whereas MrGSTK fell in arthropods GST kappa. It is interesting to note that MrGSTD and MrGSTK shared only 21% identity; it indicated their structural difference. Structural analysis indicated that MrGSTD to be canonical dimer like shape and MrGSTK appeared to be butterfly dimer like shape, in spite of four β-sheets being conserved in both GSTs. Tissue specific gene expression analysis showed that both MrGSTD and MrGSTK are highly expressed in immune organs such as haemocyte and hepatopancreas, respectively. To understand the role of mRNA modulation of MrGSTD and MrGSTK, the prawns were inducted with oxidative stressors such as bacteria (Vibrio harveyi), virus [white spot syndrome virus (WSSV)] and heavy metal, cadmium (Cd). The analysis revealed an interesting fact that both MrGSTD and MrGSTK showed higher (P