Glycosylation Affects both the Three-Dimensional Structure and Antibody Binding Properties of the HIV-1IIIB GP120 Peptide RP135
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- 作者：Xiaolin Huang ; Joseph J. Barchi ; Jr. ; Feng-Di T. Lung ; Peter P. Roller ; Peter L. Nara ; Jeff Muschik ; and Robert R. Garrity
- 刊名：Biochemistry
- 出版年：1997
- 出版时间：September 9, 1997
- 年：1997
- 卷：36
- 期：36
- 页码：10846 - 10856
- 全文大小：258K
- 年卷期：v.36,no.36(September 9, 1997)
- ISSN：1520-4995
文摘
We have prepared glycosylated analogues of the principalneutralizing determinant of gp120and studied their conformations by NMR and circular dichroismspectroscopies. The 24-residue peptidefrom the HIV-1IIIB isolate (residues 308-331) designatedRP135, which contains the immunodominanttip of the V3 loop, was glycosylated with both N- and O-linked sugars.The structures of two glycopeptides,one with an N-linked 
-glucosamine (RP135NG) and theother with two O-linked 
-galactosamine units(RP135digal), were studied by NMR and circular dichroismspectroscopies. Molecular dynamics calculationsbased on the NMR data obtained in water solutions were performed toexplore the conformational substatessampled by the glycopeptides. The data showed that covalentlylinking a carbohydrate to the peptide hasa major effect on the local conformation and imparts additional minorchanges at more distant sites ofpartially defined secondary structure. In particular, thetransient -type turn comprised of the -Gly-Pro-Gly-Arg- segment at the "tip" of the V3 loop is more highlypopulated in RP135digal than in the nativepeptide and N-linked analogue. Binding data for the glycopeptideswith 0.5, a monoclonal antibodymapped to the RP135 sequence, revealed a significant enhancement inbinding for RP135digal as comparedwith the native peptide, whereas binding was reduced for the N-linkedglycopeptide. These data showthat glycosylation of V3 loop peptides can affect their conformationsas well as their interactions withantibodies. The design of more ordered and biologically relevantconformations of immunogenic regionsfrom gp120 may aid in the design of more effective immunogens for HIV-1vaccine development.
-glucosamine (RP135NG) and theother with two O-linked -galactosamine units(RP135digal), were studied by NMR and circular dichroismspectroscopies. Molecular dynamics calculationsbased on the NMR data obtained in water solutions were performed toexplore the conformational substatessampled by the glycopeptides. The data showed that covalentlylinking a carbohydrate to the peptide hasa major effect on the local conformation and imparts additional minorchanges at more distant sites ofpartially defined secondary structure. In particular, thetransient -type turn comprised of the -Gly-Pro-Gly-Arg- segment at the "tip" of the V3 loop is more highlypopulated in RP135digal than in the nativepeptide and N-linked analogue. Binding data for the glycopeptideswith 0.5, a monoclonal antibodymapped to the RP135 sequence, revealed a significant enhancement inbinding for RP135digal as comparedwith the native peptide, whereas binding was reduced for the N-linkedglycopeptide. These data showthat glycosylation of V3 loop peptides can affect their conformationsas well as their interactions withantibodies. The design of more ordered and biologically relevantconformations of immunogenic regionsfrom gp120 may aid in the design of more effective immunogens for HIV-1vaccine development.