title: A Homology Based Model and Virtual Screening of Inhibitors for Human Geranylgeranyl Transferase 1 (GGTase1).
abstract: Protein prenylation is a post translational modification that is indispensable for Ras-Rho mediated tumorigenesis. In mammals, three enzymes namely protein farnesyltransferase (FTase), geranylgeranyl transferase1 (GGTase1), and geranylgeranyl transferase2 (GGTase2) were found to be involved in this process. Usually proteins of Ras family will be farnesylated by FTase, Rho family will be geranylgeranylated by GGTase1. GGTase2 is exclusive for geranylgeranylating Rab protein family. FTase inhibitors such as FTI- 277 are potent anti-cancer agents in vitro. In vivo, mutated Ras proteins can either improve their affinity for FTase active site or undergo geranylgeranylation which confers resistance and no activity of FTase inhibitors. This led to the development of GGTase1 inhibitors. A well-defined 3-D structure of human GGTase1 protein is lacking which impairs its in silico and rational designing of inhibitors. A 3-D structure of human GGTase1 was constructed based on primary sequence available and homology modeling to which pubchem molecules library was virtually screened through AutoDock Vina. Our studies show that natural compounds Camptothecin (-8.2 Kcal/mol), Curcumin (-7.3 Kcal/mol) have higher binding affinities to GGTase-1 than that of established peptidomimetic GGTase-1 inhibitors such as GGTI-297 (-7.5 Kcal/mol), GGTI-298 (-7.5 Kcal/mol), CHEMBL525185 (-7.2 Kcal/mol).
authors.affiliation: Department of Biotechnology and Bioinformatics ; Authors contributed equally.
authors.forename: Mallikarjuna
authors.initials: M
authors.lastname: Thippanna
authors.affiliation: Department of Zoology ; Authors contributed equally.
authors.forename: Parasuraman Aiya
authors.initials: PA
authors.lastname: Subramani
authors.affiliation: Departments of Genetics and Genomics, Yogi Vemana University, Kadapa, Andhra Pradesh, India-516 003.
authors.forename: Dakshayani
authors.initials: D
authors.lastname: Lomada
authors.affiliation: Department of Zoology.
authors.forename: Venkata Ramireddy
authors.initials: VR
authors.lastname: Narala
authors.affiliation: Department of Biotechnology and Bioinformatics.
authors.forename: Madhava C
authors.initials: MC
authors.lastname: Reddy
keywords: Auto dock; Camptothecin; GGTase1; Prenylation; Rho