Back to Search
Start Over
Kinetic and structural characterization of amyloid-β peptide hydrolysis by human angiotensin-1-converting enzyme.
- Source :
-
The FEBS journal [FEBS J] 2016 Mar; Vol. 283 (6), pp. 1060-76. Date of Electronic Publication: 2016 Feb 09. - Publication Year :
- 2016
-
Abstract
- Unlabelled: Angiotensin-1-converting enzyme (ACE), a zinc metallopeptidase, consists of two homologous catalytic domains (N and C) with different substrate specificities. Here we report kinetic parameters of five different forms of human ACE with various amyloid beta (Aβ) substrates together with high resolution crystal structures of the N-domain in complex with Aβ fragments. For the physiological Aβ(1-16) peptide, a novel ACE cleavage site was found at His14-Gln15. Furthermore, Aβ(1-16) was preferentially cleaved by the individual N-domain; however, the presence of an inactive C-domain in full-length somatic ACE (sACE) greatly reduced enzyme activity and affected apparent selectivity. Two fluorogenic substrates, Aβ(4-10)Q and Aβ(4-10)Y, underwent endoproteolytic cleavage at the Asp7-Ser8 bond with all ACE constructs showing greater catalytic efficiency for Aβ(4-10)Y. Surprisingly, in contrast to Aβ(1-16) and Aβ(4-10)Q, sACE showed positive domain cooperativity and the double C-domain (CC-sACE) construct no cooperativity towards Aβ(4-10)Y. The structures of the Aβ peptide-ACE complexes revealed a common mode of peptide binding for both domains which principally targets the C-terminal P2' position to the S2' pocket and recognizes the main chain of the P1' peptide. It is likely that N-domain selectivity for the amyloid peptide is conferred through the N-domain specific S2' residue Thr358. Additionally, the N-domain can accommodate larger substrates through movement of the N-terminal helices, as suggested by the disorder of the hinge region in the crystal structures. Our findings are important for the design of domain selective inhibitors as the differences in domain selectivity are more pronounced with the truncated domains compared to the more physiological full-length forms.<br />Database: The atomic coordinates and structure factors for N-domain ACE with Aβ peptides 4-10 (5AM8), 10-16 (5AM9), 1-16 (5AMA), 35-42 (5AMB) and (4-10)Y (5AMC) complexes have been deposited in the Protein Data Bank, Research Collaboratory for Structural Bioinformatics, Rutgers University, New Brunswick, NJ, USA (http://www.rcsb.org/).<br /> (© 2016 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)
- Subjects :
- Amino Acid Sequence
Amyloid beta-Peptides genetics
Binding Sites
Crystallography, X-Ray
Genetic Variation
Humans
Hydrolysis
In Vitro Techniques
Kinetics
Models, Molecular
Molecular Sequence Data
Peptide Fragments chemistry
Peptide Fragments genetics
Peptide Fragments metabolism
Peptidyl-Dipeptidase A genetics
Protein Interaction Domains and Motifs
Recombinant Proteins chemistry
Recombinant Proteins genetics
Recombinant Proteins metabolism
Substrate Specificity
Amyloid beta-Peptides chemistry
Amyloid beta-Peptides metabolism
Peptidyl-Dipeptidase A chemistry
Peptidyl-Dipeptidase A metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1742-4658
- Volume :
- 283
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- The FEBS journal
- Publication Type :
- Academic Journal
- Accession number :
- 26748546
- Full Text :
- https://doi.org/10.1111/febs.13647