GASP‐1 and GASP‐2, two closely structurally related proteins with a functional duality in antitrypsin inhibition specificity: a mechanistic point of view. (10th October 2019)

• Record Type: Journal Article
• Authors: Parenté, Alexis; Di Meo, Florent; Lapeyronie, Eric; Al Mansi, Montasir; Delourme, Didier; Pélissier, Patrick; Brémaud, Laure; Trouillas, Patrick; Blanquet, Véronique
• Is Part Of: FEBS journal. Volume 287:Number 5(2020)
• Page Start: 909
• Page End: 924
• Publication Date: 2019-10-10
• Subjects: antiprotease -- GASP/WFIKKN -- inhibition mechanism -- Kunitz domain -- molecular dynamics; Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pathology, Molecular -- Periodicals; 572
• DOI: 10.1111/febs.15072
• Languages: English
• ISSNs: 1742-464X

Abstract

Abstract : While GASP‐1 and GASP‐2 proteins are known to regulate myogenesis by inhibiting myostatin, their structural organization suggests a putative role as multivalent protease inhibitors controlling different protease activities. In this study, we show the noncompetitive and competitive antitrypsin activities of the full‐length GASP‐1 and GASP‐2 proteins, respectively, by using a bacterial system production and in vitro enzymatic experiments. The role of the second Kunitz domain in this functional duality is described by assessing the antitrypsin activity of GASP‐1/2 chimeric proteins. Molecular dynamics simulations support the experimental data to rationalize differences in binding modes between trypsin and the GASP‐1 and GASP‐2 second Kunitz domains. A new inhibition mechanism was evidenced for the second Kunitz domain of GASP‐2, in which the conventional cationic residue of trypsin inhibitors was substituted by the strongly interacting glutamine residue. Abstract : By comparative analysis of trypsin inhibitor activity, we showed that the full‐length mGASP‐2 protein exhibits a competitive‐type inhibition mechanism whereas the mGASP‐1 protein presents a noncompetitive antitrypsin activity. Molecular modeling and dynamic simulations supported this functional duality, rationalizing how the second Kunitz domain of GASP‐1 and GASP‐2 were implicated in the antitrypsin inhibition specificity based on the description of the highly dynamic modes of binding.