Change in size of the envelope glycoprotein of a human immunodeficiency virus 1 (HIV 1) strain.
ABSTRACT A strain of HIV 1 (PA 40), isolated from a patient with AIDS, showed a size variation of its external glycoprotein. This glycoprotein had an estimated molecular weight of 105 Kd and differed from that of both HIV 1 IIIb and HIV 2 Rod strains. The protein was derived from a bigger (140 Kd) precursor, detectable only in the infected cells and could incorporate labeled glucose in its prosthetic portion. The change in size of the external glycoprotein may be the result of envelope sequence variations since the unglycosylated form of the envelope precursor of PA 40 strain, detected in tunicamycin treated cells, was smaller than that of the HIV 1 IIIb strain. The different size of the external glycoprotein is a further aspect of the variability of the biological characteristic of HIV 1 strains and might be correlated with the emergence of more virulent variants which arose during the progression of the clinical disease.
SourceAvailable from: Haixia XiaoProtein & Cell 02/2012; 3(2):160. DOI:10.1007/s13238-012-2030-9
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ABSTRACT: There is a great need for new vaccine development against influenza A viruses due to the drawbacks of traditional vaccines that are mainly prepared using embryonated eggs. The main component of the current split influenza A virus vaccine is viral hemagglutinin (HA) which induces a strong antibody-mediated immune response. To develop a modern vaccine against influenza A viruses, the current research has been focused on the universal vaccines targeting viral M2, NP and HA proteins. Crystallographic studies have shown that HA forms a trimer embedded on the viral envelope surface, and each monomer consists of a globular head (HA1) and a "rod-like" stalk region (HA2), the latter being more conserved among different HA subtypes and being the primary target for universal vaccines. In this study, we rationally designed the HA head based on the crystal structure of the 2009-pandemic influenza A (H1N1) virus HA as a model, tested its immunogenicity in mice, solved its crystal structure and further examined its immunological characteristics. The results show that the HA globular head can be easily prepared by in vitro refolding in an E. coli expression system, which maintains its intact structure and allows for the stimulation of a strong immune response. Together with recent reports on some similar HA globular head preparations we conclude that structure-based rational design of the HA globular head can be used for subtype-specific vaccines against influenza viruses.Protein & Cell 12/2011; 2(12):997-1005. DOI:10.1007/s13238-011-1134-y