Effect of Glycosylation on an Immunodominant Region in the V1V2 Variable Domain of the HIV-1 Envelope gp120 Protein
Fig 4
Net charge distribution of the variable regions.
Using the same input data as in Fig 3, charge variability in the V-1V5 regions and the V2 epitope region is shown. The V3 loop and V2 epitope region, despite being conserved in terms of length and number of glycosylation sites (Fig 3), both show a great deal of variation in net charge, comparable to the level of diversity found in hyper-variable regions. Net charge is calculated as the sum of positive and negative charges, where amino acid residues E and D are assigned -1, and K, R, and H are assigned +1. The V2 epitope region, V3 and V2 tend to be positively charged; V1, V4, V5 tend to be negatively charged.