Self-assembly of angiotensin-converting enzyme inhibitors captopril and lisinopril and their crystal structures

Castelletto, V. ORCID: https://orcid.org/0000-0002-3705-0162, Seitsonen, J., Ruokolainen, J., Barnett, S. A., Sandu, C. and Hamley, I. W. ORCID: https://orcid.org/0000-0002-4549-0926 (2021) Self-assembly of angiotensin-converting enzyme inhibitors captopril and lisinopril and their crystal structures. Langmuir, 37 (30). pp. 9170-9178. ISSN 0743-7463 doi: 10.1021/acs.langmuir.1c01340

Abstract/Summary

The peptide angiotensin-converting enzyme inhibitors captopril and lisinopril are unexpectedly shown to exhibit critical aggregation concentration (CAC) behavior through measurements of surface tension, electrical conductivity, and dye probe fluorescence. These three measurements provide similar values for the CAC, and there is also evidence from circular dichroism spectroscopy for a possible conformational change in the peptides at the same concentration. Cryogenic transmission electron microscopy indicates the formation of micelle-like aggregates above the CAC, which can thus be considered a critical micelle concentration, and the formation of aggregates with a hydrodynamic radius of ∼6–7 nm is also evidenced by dynamic light scattering. We also used synchrotron radiation X-ray diffraction to determine the single-crystal structure of captopril and lisinopril. Our results improve the accuracy of previous data reported in the literature, obtained using conventional X-ray sources. We also studied the structure of aqueous solutions containing captopril or lisinopril at high concentrations. The aggregation may be driven by intermolecular interactions between the proline moiety of captopril molecules or between the phenylalanine moiety of lisinopril molecules.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/99517
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry
Publisher	American Chemical Society
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