Since 1981, in which the first case of HIV-1 infection was reported, a large amount of research has been devoted to dealing with this challenging problem [1]. It is well known that the main factor associated with HIV-1 infection is the interaction between HIV-1 envelope glycoprotein (gp) 120 and the lymphocyte surface receptors, CD4 [2]. Therefore, destroying or denaturation of chemical bonds of gp120 can be treated as one of the most effective approaches to achieve this goal. For example, Mastro et al have demonstrated that the anti HIV-1 property of silver nanoparticles is mainly due to their influence on the disulfide bonds of gp120 [3]. Recently, the interaction between an Ag atom separated from silver nanoparticles and disulfide bond of cystine units of gp120 was considered as one of the possible mechanisms [4]. In the present study the applicability of this mechanism for the other transition metals (TM)was investigated by using dimethyl disulfide (DMDS) as the molecular model.
