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Scaffold stability and P14′ residue steric hindrance in the differential inhibition of FXIIa by Aedes aegypti trypsin inhibitor versus Infestin-4

Kazal-type protease inhibitors strictly regulate Factor XIIa (FXIIa), a blood-clotting serine protease. However, when negatively charged surface of prosthetic device come into contact with FXII, it undergoes conformational change and auto-activation, leading to thrombus formation. Some research sugg...

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Autores principales: Walvekar, Varsha Ashok, Ramesh, Karthik, Kannan, Muthu, Kini, R. Manjunatha, Sivaraman, J., Mok, Yu Keung
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Portland Press Ltd. 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9112662/
https://www.ncbi.nlm.nih.gov/pubmed/35485437
http://dx.doi.org/10.1042/BSR20220421
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author Walvekar, Varsha Ashok
Ramesh, Karthik
Kannan, Muthu
Kini, R. Manjunatha
Sivaraman, J.
Mok, Yu Keung
author_facet Walvekar, Varsha Ashok
Ramesh, Karthik
Kannan, Muthu
Kini, R. Manjunatha
Sivaraman, J.
Mok, Yu Keung
author_sort Walvekar, Varsha Ashok
collection PubMed
description Kazal-type protease inhibitors strictly regulate Factor XIIa (FXIIa), a blood-clotting serine protease. However, when negatively charged surface of prosthetic device come into contact with FXII, it undergoes conformational change and auto-activation, leading to thrombus formation. Some research suggests that Kazal-type protease inhibitor specificity against FXIIa is governed solely by the reactive-site loop sequence, as this sequence makes most-if not all-of the direct contacts with FXIIa. Here, we sought to compare the inhibitory properties of two Kazal-type inhibitors, Infestin-4 (Inf4), a potent inhibitor of FXIIa, and Aedes aegypti trypsin inhibitor (AaTI), which does not inhibit FXIIa, to better understand Kazal-type protease specificity and determine the structural components responsible for inhibition. There are only three residue differences in the reactive-site loop between AaTI and Inf4. Through site-directed mutagenesis, we show that the reactive-site loop is only partially responsible for the inhibitory specificity of these proteases. The protein scaffold of AaTI is unstable due to an elongated C5C6 region. Through chimeric study, we show that swapping the protease-binding loop and the C5C6 region from Inf4 with that of AaTI can partially enhance the inhibitory activity of the AaTI_Inf4 chimera. Furthermore, the additional substitution of Asn at the P14′ position of AaTI with Gly (Gly27 in Inf4) absolves the steric clashing between AaTI and the surface 140-loop of FXIIa, and increases the inhibition of the chimeric AaTI to match that of wild-type Inf4. Our findings suggest that ancillary regions in addition to the reactive-site loop sequence are important factors driving Kazal-type inhibitor specificity.
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spelling pubmed-91126622022-05-31 Scaffold stability and P14′ residue steric hindrance in the differential inhibition of FXIIa by Aedes aegypti trypsin inhibitor versus Infestin-4 Walvekar, Varsha Ashok Ramesh, Karthik Kannan, Muthu Kini, R. Manjunatha Sivaraman, J. Mok, Yu Keung Biosci Rep Enzymology Kazal-type protease inhibitors strictly regulate Factor XIIa (FXIIa), a blood-clotting serine protease. However, when negatively charged surface of prosthetic device come into contact with FXII, it undergoes conformational change and auto-activation, leading to thrombus formation. Some research suggests that Kazal-type protease inhibitor specificity against FXIIa is governed solely by the reactive-site loop sequence, as this sequence makes most-if not all-of the direct contacts with FXIIa. Here, we sought to compare the inhibitory properties of two Kazal-type inhibitors, Infestin-4 (Inf4), a potent inhibitor of FXIIa, and Aedes aegypti trypsin inhibitor (AaTI), which does not inhibit FXIIa, to better understand Kazal-type protease specificity and determine the structural components responsible for inhibition. There are only three residue differences in the reactive-site loop between AaTI and Inf4. Through site-directed mutagenesis, we show that the reactive-site loop is only partially responsible for the inhibitory specificity of these proteases. The protein scaffold of AaTI is unstable due to an elongated C5C6 region. Through chimeric study, we show that swapping the protease-binding loop and the C5C6 region from Inf4 with that of AaTI can partially enhance the inhibitory activity of the AaTI_Inf4 chimera. Furthermore, the additional substitution of Asn at the P14′ position of AaTI with Gly (Gly27 in Inf4) absolves the steric clashing between AaTI and the surface 140-loop of FXIIa, and increases the inhibition of the chimeric AaTI to match that of wild-type Inf4. Our findings suggest that ancillary regions in addition to the reactive-site loop sequence are important factors driving Kazal-type inhibitor specificity. Portland Press Ltd. 2022-05-16 /pmc/articles/PMC9112662/ /pubmed/35485437 http://dx.doi.org/10.1042/BSR20220421 Text en © 2022 The Author(s). https://creativecommons.org/licenses/by/4.0/This is an open access article published by Portland Press Limited on behalf of the Biochemical Society and distributed under the Creative Commons Attribution License 4.0 (CC BY) (https://creativecommons.org/licenses/by/4.0/) .
spellingShingle Enzymology
Walvekar, Varsha Ashok
Ramesh, Karthik
Kannan, Muthu
Kini, R. Manjunatha
Sivaraman, J.
Mok, Yu Keung
Scaffold stability and P14′ residue steric hindrance in the differential inhibition of FXIIa by Aedes aegypti trypsin inhibitor versus Infestin-4
title Scaffold stability and P14′ residue steric hindrance in the differential inhibition of FXIIa by Aedes aegypti trypsin inhibitor versus Infestin-4
title_full Scaffold stability and P14′ residue steric hindrance in the differential inhibition of FXIIa by Aedes aegypti trypsin inhibitor versus Infestin-4
title_fullStr Scaffold stability and P14′ residue steric hindrance in the differential inhibition of FXIIa by Aedes aegypti trypsin inhibitor versus Infestin-4
title_full_unstemmed Scaffold stability and P14′ residue steric hindrance in the differential inhibition of FXIIa by Aedes aegypti trypsin inhibitor versus Infestin-4
title_short Scaffold stability and P14′ residue steric hindrance in the differential inhibition of FXIIa by Aedes aegypti trypsin inhibitor versus Infestin-4
title_sort scaffold stability and p14′ residue steric hindrance in the differential inhibition of fxiia by aedes aegypti trypsin inhibitor versus infestin-4
topic Enzymology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9112662/
https://www.ncbi.nlm.nih.gov/pubmed/35485437
http://dx.doi.org/10.1042/BSR20220421
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