Structure-function studies of Bubalus bubalis lingual antimicrobial peptide analogs

详细信息    查看全文

• 作者：Dhruba Jyoti Kalita ; Ashok Kumar and Satish Kumar
• 关键词：Antimicrobial peptide ; Circular Dichroism spectroscopy ; β ; structure ; Minimum Inhibitory Concentration
• 刊名：Veterinary Research Communications
• 出版年：2009
• 出版时间：February, 2009
• 年：2009
• 卷：33
• 期：2
• 页码：149-161
• 全文大小：235.4 KB

文摘

Antimicrobial peptides expressed on different epithelial lining are major components of the innate immune system. Based on the deduced amino acid sequence of Bubalus bubalis lingual antimicrobial peptide (LAP) cDNA (Accession No. DQ458768), five overlapping peptides LAP23–55, LAP42–64, LAP21–64, LAP1–26 and LAP1–64 were synthesized using solid phase fluorenylmethoxycarbonyl (Fmoc) chemistry. Circular Dichroism spectroscopy of synthesized peptides revealed predominantly β-structure for LAP23–55, LAP42−64 and LAP21–64 with less α-helix in different solutions. Quantitation of secondary structure indicated the highest β-structure for all these three peptides in membrane mimetic SDS solution. The helicogenic solvent TFE could not induce helix in LAP23–55 however TFE induced helical propensity was observed in LAP42–64 and LAP21–64. The quantitation of secondary structure indicated the highest ordered structure for LAP23–55 followed by LAP42–64 and LAP21–64. The antibacterial activity of LAP23–55 was found to be more potent against Staphylococcus aureus, Listeria monocytogens, Escherichia coli and Salmonella typhimurium followed by LAP42–64 and LAP21–64. Minimum inhibitory concentration (MIC) also showed similar trend with lowest value for LAP23–55 followed by LAP42–64 and LAP21–64. Haemolysis and cytotoxicity was observed above 3 fold for LAP21–64, above six fold for LAP23–55 and LAP42–64 of their MIC. The LAP1–26 and LAP1–64 could not produce any characteristic CD spectra and did not show any antimicrobial activity, indicating that N- terminal of the peptide negates the antimicrobial activity.