The purpose of this study was to characterize major allergens of Indian scad (Decapterus russelli) which is among the most commonly consumed fish in Malaysia. Raw and cooked extracts of the fish were prepared. Protein profiles and IgE binding patterns were produced by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting using sera from subjects with fish allergy. The major allergens of the fish were then identified by two-dimensional electrophoresis (2-DE), followed by mass spectrometry of the peptide digests. The SDS-PAGE of the raw extract revealed 27 protein fractions over a wide molecular weight range, while the cooked extract demonstrated only six protein fractions. The 1-DE immunoblotting detected 14 IgE-binding proteins, with a molecular weight range from 90 to < 6.5 kDa. Three protein fractions with molecular weights of approximately 51, 46 and 12 kDa were identified as the major allergens of this fish. The approximately 12 kDa band was a heat-resistant protein while the approximately 51 and 46 kDa proteins were sensitive to heat. The 2-DE gel profile of the raw extract demonstrated > 100 distinct protein spots and immunoblotting detected at least 10 different major IgE reactive spots with molecular masses as expected and isoelectric point (pI) values ranging from 4.0 to 7.0. A comparison of the major allergenic spot sequences of the 12 kDa proteins with known protein sequences in databases revealed extensive similarity with fish parvalbumin. In conclusion, this study demonstrated that a parvalbumin which is similar to Gad c 1 is the major allergen of Indian scad. Interestingly, we also detected heat-sensitive proteins as major allergenic components in our fish allergy patients.
Fish has been recognized as a source of potent allergens both in food and occupational allergy. Lutjanus argentimaculatus (red snapper) and Lutjanus johnii (golden snapper) locally known as merah and jenahak, respectively, are among the most commonly consumed fish in Malaysia. The objective of this study is to identify the IgE-binding proteins and major allergens of these species of fishes. Extracts of both fish species were prepared and fractionated by sodium dodecyl polyacrylamide gel electrophoresis (SDS-PAGE). IgE binding patterns were then demonstrated by immunoblotting using sera from patients allergic to the fishes. The raw extracts of both fish produced 26 protein bands. Both species of fishes had similar protein profiles. In cooked extracts, several protein bands in the range of about 40 to 90 kD which were present in the uncooked extracts appeared to be denatured and formed high molecular weight complexes. The immunoblotting of golden snapper and red snapper revealed 16 and 15 various IgE-binding bands, in the range of 151 to 12-11 kD, respectively. A 51 kD protein was identified as a major allergen for both fishes. A 46 kD protein was also demonstrated as a major allergen in golden snapper and a 42 kD protein was also seen as a major allergen in red snapper. A heat-resistant protein of ~12 kD which is equivalent in size with fish parvalbumin was demonstrated only as minor allergen for both fishes.
This study examined the effect of dietary prebiotics and probiotics after 16 weeks, followed by 8 weeks of post feeding trial with the control unsupplemented diet on haematological and immune response against Aeromonas hydrophila infection in Channa striata fingerlings. Fish were raised on a 40% protein and 12% lipid feed containing three commercial prebiotics (β-glucan, GOS or galacto-oligosaccharide, MOS or mannan-oligosaccharide); and two probiotics- (Saccharomyces cerevisiae, Lactobacillus acidophilus), respectively and a control. Throughout the study, supplementation with dietary prebiotics and probiotics led to significant (P
A 60-day feeding trial was conducted to determine the effects of palm oil blended with oxidized and non-oxidized fish oil on growth performances, hematology, and non-specific immune response in juvenile Japanese sea bass, Lateolabrax japonicas. Japanese sea bass (1.73 ± 0.01 g) were fed seven experimental diets containing 100 g/kg of dietary lipid in forms of palm oil (10P), fish oil (10F), fish oil blended with palm oil at different ratios, 6:4 (6F4P) and 4:6 (4F6P), oxidized fish oil (10OF), and oxidized fish oil blended with palm oil at different ratios, 6:4 (6OF4P) and 4:6 (4OF6P). After the feeding trial, the following results were illustrated. No significant effects were observed in survival, feed conversion ratio, condition factor, and hematocrit after feeding with experimental diets for 60 days. The relatively higher specific growth rate and hematology were observed in 6F4P. Furthermore, both palm oil and oxidized fish oil acted as a negatively on serum lysozyme activity (P < 0.05). This study suggested that a ration of 6F4P is recommended as an innocuous ratio for Japanese sea bass. Furthermore, according to the present investigation, palm oil seems to have the ability to improve the protein efficiency when added to oxidized fish diets as well as a positive trend to the growth performance (P > 0.05).
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.