Preliminary Study On Proteins Of Human Metapneumovirus Chinese Isolate And Prediction Of The Glycation Sites And Phosphorylation Sites Of Fusion Protein

PARTⅠ: Preliminary study on proteins of human metapneumovirus Chinese isolateObjective: Human metapneumovirus (hMPV), initially described in 2001, is an enveloped RNA virus of the genus Metapneumovirus, subfamily Pneumovirinae, family Paramyxoviridae. Here we sought to clarify basic features of human metapneumovirus proteins.Methods: Rabbits were immunized with inactivated virons of hMPV Chinese first isolate, CHN05-01, to yield anti-hMPV antiserum. Antiserum was subsequently used as primary antibody to detect hMPV proteins by Western blotting. NetNglyc1.0 server, NetOglyc 3.1server and the NetPhos 2.0 server were applied for predicting potential glycosylation and phosphorylation sites of proteins of prototype virus of subtype A, CAN97- 83.Results: The highest reactive titer of the antiserum with hMPV antigens reached 1:500 in ELISA. Potential glycosylation sites of G protein and phosphorylation sites of P protein were greatest among all hMPV proteins. G protein was shown a narrow band with molecular weight between 55 and 72kDa (approximately 68kDa), indicating its glycosylation level being consistent and remarkably different from that of CAN99-80 and CAN99-81. F1 subunit of fusion protein displayed molecular weight between 40 and 55kDa (approximately 48 kDa), which is in consistent with previous reports.Conclusion: Basic features of two major membrane proteins of Chinese human metapneumovirus isolate were clarified, which will benefit future studies on protein funtion and pathogenesis of this virus.PARTⅡ: Prediction of the glycation sites and phosphorylation sites of human metapneumovirus fusion proteinObjective: To predict the glycosylation sites and phosphorylation sites of human metapneumovirus fusion protein.Methods: Position and score of N-Glycosylation sites, O-glycosylation sites, glycation sites ofεamino groups of lysines, phosphorylation sites in fusion protein of 4 subtype representative strains were predicted by using neural network.Results: Fusion protein of 4 subtype representative strains showed conservative N-Glycosylation sites, glycation sites ofεamino groups of lysines, phosphorylation sites, but no same O-glycosylation sites. Four regions of B cell epitopes in fusion protein of A2 subtype strain did not show glycation sites and phosphorylation sites.Conlusion: The glycation sites and phosphorylation sites of fusion protein are successfully predicted. This might be proven beneficial for studies on functions of protein glycation and immunological significance and polypeptide vaccine design.