Substrate specificity of avian influenza H5N1 neuraminidase

• 作者: Alita Kongchanagul Chompunuch Boonarkart Kanokwan Kittiniyom Krisada Chaichuen Naruthai Onsirisakul Ornpreya Suptawiwat Pilaipan Puthavathana Prasert Auewarakul Shin-ichi Nakakita Yasuo Suzuki
• 来源期刊: 世界病毒学杂志
• 学科: 医学
• 关键词: H5N1 AVIAN INFLUENZA virus NEURAMINIDASE Sialic acid ADAPTATION Substrate PREFERENCE
• 年，卷（期）: 2014,（4）
• 页码范围: 30-36
• 页数: 7页
• 分类号: R

摘要

AIM:To characterise neuraminidase(NA)substrate specificity of avian influenza H5N1 strains from humans and birds comparing to seasonal influenza virus.METHODS:Avian influenza H5N1 strains from humans and birds were recruited for characterising their NA substrate specificity by using a modified commercial fluorescence Amplex Red assay.This method can identify the preference ofα2,6-linked sialic acid orα2,3-linked sialic acid.Moreover,to avoid the bias of input virus,reverse genetic virus using NA gene from human isolated H5N1 were generated and used to compare with the seasonal influenza virus.Lastly,the substrate specificity profile was further confirmed by high-performance liquid chromatography(HPLC)analysis of the enzymatic product.RESULTS:The H5N1 NA showed higher activity onα2,3-linked sialic acid thanα2,6-linked(P<0.0001).To compare the NA activity between the H5N1 and seasonal influenza viruses,reverse genetic viruses carrying the NA of H5N1 viruses and NA from a seasonal H3N2 virus was generated.In these reverse genetic viruses,the NA activity of the H5N1 showed markedly higher activity againstα2,3-linked sialic acid than that of the H3N2 virus,whereas the activities onα2,6-linkage were comparable.Interestingly,NA from an H5N1 human isolate that was previously shown to have heamagglutinin(HA)with dual specificity showed reduced activity onα2,3-linkage.To confirm the substrate specificity profile,HPLC analytic of enzymatic product was performed.Similar to Amplex red assay,H5N1 virus showed abundant preference onα2,3-linked sialic acid.CONCLUSION:H5N1 virus maintains the avian specific NA and NA changes may be needed to accompany changes in HA receptor preference for the viral adaptation to humans.