김정곤 박사 제1저자 CBP Part C 논문게재

우리 연구실의 김정곤 박사가 제 1저자로 Comparative Biochemistry and Physiology Part C: Toxicology and Pharmacology에 D. magna catalase cloning에 대한 논문을 게재하게 되었습니다. 이 연구는 수생태복원사업단에서 수행한 연구의 일부입니다. 축하합니다. Molecular cloning of Daphnia magna catalase and its biomarker potential against oxidative stresses Jungkon Kim1, Sunmi Kim1, Kwang Wook An2, Cheol Young Choi2, Sungkyu Lee3, Kyungho Choi1* 요약 Catalase is an important antioxidant enzyme that protects aerobic organisms against oxidative damage by degrading hydrogen peroxide to oxygen and water. Catalase mRNAs have been cloned from many species and employed as useful biomarkers of oxidative stress. In the present study, we cloned the cDNA from the catalase gene in Daphnia magna, analyzed its catalytic properties, and investigated mRNA expression patterns after the exposure to known oxidative stressors. The catalase proximal heme-ligand signature sequence, FDRERISERVVHAKGSGA, and the proximal active site signature, RLFSYTDTH, are highly conserved. The variation of catalase mRNA expression in D. magna was quantified by real-time PCR, and the results indicated that catalase expression was up-regulated after exposure to UV-B light or cadmium (Cd). The activity of catalase enzyme also showed a similar increasing pattern when exposed to these model stressors. The full-length catalase cDNA of D. magna was cloned using mixed primers by the method of 3’ and 5’ rapid amplification of cDNA ends PCR. The cDNA sequence consists of 1,515 nucleotides, encoding 504 amino acids. Sequence comparison showed that the deduced amino acid sequence of D. magna shared 73%, 72%, 71% and 70% identity with that of Chlamys farreri, Fenneropenaeus chinensis, Litopenaeus vannamei and Anopheles gambiae, respectively. This study shows that the catalase mRNA from D. magna could be successfully employed as a biomarker of oxidative stress, which is a common mode of toxicity for many water contaminants.