Direct interaction between a human digestive protease and the mucoadhesive poly(acrylic acid)

Carboxypeptidase A1 has been the subject of extensive research in the last 30 y and is one of the most widely studied zinc metalloenzymes. However, the three-dimensional structure of the human form of the enzyme is not yet available. This report describes the three-dimensional structure of human car...

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Bibliographic Details
Authors: Pallarès i Goitiz, Irantzu|||0000-0002-8205-2060, Fernández Fleischhauer, Daniel|||0000-0002-6221-152X, Comellas-Bigler, Mireia, Fernández-Recio, Juan|||0000-0002-3986-7686, Ventura, Salvador|||0000-0002-9652-6351, Avilés, Francesc Xavier|||0000-0002-1399-6789, Bode, Wolfram, Vendrell i Roca, Josep|||0000-0002-9378-4742
Format: article
Publication Date:2008
Country:España
Institution:Universitat Autònoma de Barcelona
Repository:Dipòsit Digital de Documents de la UAB
Language:English
OAI Identifier:oai:ddd.uab.cat:27763
Online Access:https://ddd.uab.cat/record/27763
https://dx.doi.org/urn:doi:10.1107/S0907444908013474
Access Level:Open access
Keyword:Cristal·lografia
Crystallography
Carboxypeptidase A1
Mucoadhesive polymers
Zinc metalloenzymes
Digestive proteases
Description
Summary:Carboxypeptidase A1 has been the subject of extensive research in the last 30 y and is one of the most widely studied zinc metalloenzymes. However, the three-dimensional structure of the human form of the enzyme is not yet available. This report describes the three-dimensional structure of human carboxypeptidase A1 (hCPA1) derived from crystals that belong to the tetragonal space group P43212 and diffract to 1.6 Å resolution. A description of the ternary complex hCPA1-Zn2+-poly(acrylic acid) is included as a model of the interaction of mucoadhesive polymers with proteases in the gastrointestinal tract. The direct mode of interaction between poly(acrylic acid) and the active site of the target protease was confirmed by in vitro inhibition assays. The structure was further analyzed in silico through the optimal docking-area method. The characterization of binding sites on the surface of hCPA1 and a comparison with other available carboxypeptidase structures provided further insights into the formation of multiprotein complexes and the activation mechanisms of carboxypeptidase zymogens. The high-resolution structure of hCPA1 provides an excellent template for the modelling of physiologically relevant carboxypeptidases and could also contribute to the design of specific agents for biomedical purposes.