In silico directed mutagenesis using software for glycosylation sites prediction as a new step in antigen design
In silico directed mutagenesis with the aim to estimate consequences of mutational pressure on number of N- and O-glycosylation sites has been proposed as an important step in antigen design. Using this kind of methodology one is able to estimate probabilities at which N- and O-glycosylation sites can be destroyed and created due to one-step missense mutations in the subsequent gene. Mutational AT-pressure has been simulated in the region of env gene coding for HIV1 gp120. Consequences of 741 amino acid substitutions have been predicted with the help of NetNGlyc 1.0 and NetOGlyc 3.1 software. The probability of O-glycosylation site destruction (2.16%) in HIV1 gp120 protein due to a single missense GC to AT mutation in env gene is higher than the probability of a new site creation (0.40%). The probability of N-glycosylation site destruction in HIV1 gp120 protein is equal to the probability of its creation (5.53%), while the number of N-glycosylation sites which can be created due to a single missense GC to AT mutation in env gene is 1.27 times higher than the number of N-glycosylation sites which can be destroyed.