Sarkar MA Kawsar, Sarkar MA Mamun, Md S Rahman, Hidetaro Yasumitsu and Yasuhiro Ozeki
Keywords: Rana catesbeiana, antibacterial, antifungal, inhibition zone, mycelial growth, lectin.
Abstract: A ?-galactoside-binding galectin-1 (RCG1) was purified from the oocytes of the American bullfrog, Rana catesbeiana by affinity column chromatography and was evaluated for its growth of inhibition effects on bacteria and fungi. Through SDS-PAGE and gel permeation chromatography, RCG1 was found to be a non-covalently-bonded dimeric protein that consisted of two 15 kDa polypeptide subunits. This lectin showed significant hemagglutinting activity against trypsinized human and rabbit erythrocytes and it was inhibited by asialofetuin, thiodigalactoside and lectose. RCG1 was screened for in vitro antibacterial activity against eleven human pathogenic bacteria and significantly inhibited the growth of gram-positive bacteria than the gram-negative bacteria. Bacillus subtilis (10±1 mm) and Bacillus cereus (8±1 mm) were exhibited the highest growth of inhibition by the lectin (250 ?g/disc). At the same time, RCG1 showed good growth inhibition against the gram-negative bacterium, Salmonella typhi but not others such as, Pseudomans sp., Escherichia coli and Vibrio cholerae. Antifungal activity also was investigated against six phytopathogenic fungi based on a food poisoning technique. Among the test fungi, the maximum inhibition of mycelial growth were observed in Fusarium equiseti (18.4±1%) followed by Colletotrichum corchori (13.3±1%) and Curvularia lunata (8.4±1%) at a concentration of the RCG1 100 ?g/ml. These results suggest that future findings of lectin applications obtained from bullfrog oocytes may be of importance to clinical microbiology and have potential drug-resistant agents.
[View Complete Article]