Protein aggregated state plays a crucial role in regulating proteins in ion channels, DNA binding, signal transduction, enzymatic actions, immune response. However, any redundancy in the association mechanism of proteins may also trigger the formation of pathogenic structures. To estimate the mechanism leading to the protein associated state, conformational dynamics of the proteins has been determined through several experi- mental and computational studies. These studies depict that the crowders, the macromolecules constituting the intracellular environment can significantly induce the formation of protein self-aggregated complex whereas some crowders can also impart a destabilising effect on protein-protein complexes. Here, we investigate the protein- protein association influenced by the macromolecular crowders using GB1 protein as the model system in a dilute medium as well as in a crowded medium. With molecular dynamic simulations, we used an enhanced sampling technique, called metadynamics that aids in facilitating the system to escape the local free energy minima traps easily, thereby accelerating the process of getting a stable conformation of protein-protein complexes.