Faaberg K S, Palmer G A, Even C, Anderson G W, Plagemann P G
Department of Microbiology, University of Minnesota, Minneapolis 55455, USA.
Virus Res. 1995 Dec;39(2-3):331-40. doi: 10.1016/0168-1702(95)00088-7.
ORF 5 encoding the primary envelope glycoprotein, VP-3P, of a highly neuropathogenic isolate of lactate dehydrogenase-elevating virus (LDV-v) has been sequenced. It exhibits 92% nucleotide identity with the ORF 5 of an LDV isolate that lacks neuropathogenicity, LDV-P, and the amino acid identities of the predicted VP-3Ps of the two strains is 90%. Most striking, however, is the absence in the ectodomain of LDV-v VP-3P of two out of three potential N-glycosylation sites present in the ectodomain of VP-3P of LDV-P. The ectodomain of VP-3P has been implicated to play an important role in host receptor interaction. VP-3P of another neuropathogenic LDV strain, LDV-C, lacks the same two N-glycosylation sites (Godeny et al., 1993). In vitro transcription/translation of the ORFs 5 of LDV-P and LDV-v indicated that all three N-glycosylation sites in the ectodomain of LDV-P VP-3P became glycosylated when synthesized in the presence of microsomal membranes, whereas the glycosylation of the ORF 5 proteins of LDV-v and LDV-C was consistent with glycosylation at a single site. No other biological differences between the neuropathogenic and non-neuropathogenic strains have been detected. They replicate with equal efficiency in mice and in primary macrophage cultures.
对乳酸脱氢酶升高病毒（LDV-v）的一种高度神经致病性分离株的主要包膜糖蛋白VP-3P的编码开放阅读框（ORF）5进行了测序。它与缺乏神经致病性的LDV分离株LDV-P的ORF 5具有92%的核苷酸同一性，并且这两种毒株预测的VP-3P的氨基酸同一性为90%。然而，最引人注目的是，在LDV-v VP-3P的胞外结构域中，LDV-P的VP-3P胞外结构域中存在的三个潜在N-糖基化位点中有两个缺失。VP-3P的胞外结构域被认为在宿主受体相互作用中起重要作用。另一种神经致病性LDV毒株LDV-C的VP-3P也缺少相同的两个N-糖基化位点（戈德尼等人，1993年）。对LDV-P和LDV-v的ORF 5进行体外转录/翻译表明，当在微粒体膜存在的情况下合成时，LDV-P VP-3P胞外结构域中的所有三个N-糖基化位点都发生了糖基化，而LDV-v和LDV-C的ORF 5蛋白的糖基化与单个位点的糖基化一致。在神经致病性和非神经致病性毒株之间未检测到其他生物学差异。它们在小鼠和原代巨噬细胞培养物中的复制效率相同。
