Ma Deying, Wang Ruiqin, Liao Wenyan, Han Zongxi, Liu Shengwang
Institute of Animal Nutrition, Northeast Agricultural University, Harbin, PR China.
J Microbiol. 2009 Oct;47(5):610-8. doi: 10.1007/s12275-009-0068-z. Epub 2009 Oct 24.
In this study, a novel avian beta-defensin (AvBD) was isolated from duck pancreas. The complete nucleotide sequence of the gene contained an 195 bp open reading frame encoding 64 amino acids. Homology, characterization and comparison of the gene with AvBD from other avian species confirmed that it was duck AvBD2. The mRNA expression of the gene was analyzed in 17 tissues from 21-day-old ducks. AvBD2 was highly expressed in the trachea, crop, heart, bone marrow, and pancreas; moderately expressed in the muscular stomach, small intestine, kidney, spleen, thymus, and bursa of Fabricius; and weakly expressed in skin. We produced and purified recombinant AvBD2 by expressing the gene in Escherichia coli. As expected, the recombinant peptide exhibited strong bactericidal properties against Bacillus cereus, Staphylococcus aureus, and Pasteurella multocida, and weak bactericidal properties against E. coli and Salmonella choleraesuis. In addition, the recombinant protein retained antimicrobial activity against S. aureus under different temperatures (range, -20 degrees C to 100 degrees C) and pH values (range, 3 to 12).
在本研究中，从鸭胰腺中分离出一种新型禽β-防御素（AvBD）。该基因的完整核苷酸序列包含一个195 bp的开放阅读框，编码64个氨基酸。该基因与其他禽类物种的AvBD的同源性、特性及比较证实它是鸭AvBD2。分析了该基因在21日龄鸭的17种组织中的mRNA表达情况。AvBD2在气管、嗉囊、心脏、骨髓和胰腺中高表达；在肌胃、小肠、肾脏、脾脏、胸腺和法氏囊中中度表达；在皮肤中弱表达。通过在大肠杆菌中表达该基因，我们制备并纯化了重组AvBD2。正如预期的那样，重组肽对蜡样芽孢杆菌、金黄色葡萄球菌和多杀性巴氏杆菌表现出较强的杀菌特性，对大肠杆菌和猪霍乱沙门氏菌表现出较弱的杀菌特性。此外，重组蛋白在不同温度（范围为-20℃至100℃）和pH值（范围为3至12）下对金黄色葡萄球菌仍保留抗菌活性。
