S195A is a Catalytically Inactive Mutant of the Protease Domain of the Urokinase-Type Plasminogen Activator (uPA)

Abstract

Epistasis is a deviation from simple additivity in the measured mutational effects in protein systems. This usually arises from complex interactions between mutated residues, and in the case of double mutations can be represented in terms of free energy differences: ε = DDG 1,2 -(DDG 1 þ DDG 2 ). Previous studies have been able to classify epistasis for pairs of mutations, however, a general mechanistic description has yet to be determined. In this study, we use physical characteristics of the mutated residues with structural features of the proteins to explain observed epistasis. A model selection procedure was used based on data from the largest, most diverse, publicly available databases. Our resulting model can explain some of the observed epistasis and it consists of physically reasonable features such as charge and alpha carbon separation. These results will help in developing new methods and predictors for epistasis, and highlights the need for larger, more diverse datasets.

Urokinase plasminogen activator as an anti-metastasis target: inhibitor design principles, recent amiloride derivatives, and issues with human/mouse species selectivity

“…Like many other serine proteases, experimental validation of this mechanism has been provided via mutation of Ser195 to Ala (S195A) (Alipranti et al 2020;Gong et al 2016) or Met (S195M) (Masih et al 2020) to produce catalytically inactive variants. As with other TLSPs, most early uPA inhibitors were arginine-mimetics, comprising an aromatic moiety substituted with an amidine (Klinghofer et al 2001;Künzel et al 2002;Mackman et al 2002;Rudolph et al 2002;Stürzebecher et al 1999;Subasinghe et al 2001) or guanidine (Barber et al 2004;Fish et al 2007;Karthikeyan et al 2009;Sperl et al 2000) group.…”

Urokinase plasminogen activator as an anti-metastasis target: Inhibitor design principles, recent amiloride derivatives and issues with human/mouse species selectivity

“…Like many other serine proteases, experimental validation of this mechanism has been provided via mutation of Ser195 to Ala (S195A) (Alipranti et al 2020;Gong et al 2016) or Met (S195M) (Masih et al 2020) to produce catalytically inactive variants.…”