Selective delivery of dicarboxylates to mitochondria by conjugation to a lipophilic cation via a cleavable linker

Prag, H. A., Kula-Alwar, D., Pala, L., Caldwell, S. T. , Beach, T. E., James, A. M., Saeb-Parsy, K., Krieg, T., Hartley, R. C. and Murphy, M. P. (2020) Selective delivery of dicarboxylates to mitochondria by conjugation to a lipophilic cation via a cleavable linker. Molecular Pharmaceutics, 17(9), pp. 3526-3540. (doi: 10.1021/acs.molpharmaceut.0c00533) (PMID:32692564) (PMCID:PMC7482397)

Abstract

Many mitochondrial metabolites and bioactive molecules contain two carboxylic acid moieties that make them unable to cross biological membranes. Hence, there is considerable interest in facilitating the uptake of these molecules into cells and mitochondria, to modify or report on their function. Conjugation to the triphenylphosphonium (TPP) lipophilic cation is widely used to deliver molecules selectively to mitochondria in response to the membrane potential. However, permanent attachment to the cation can disrupt the biological function of small dicarboxylates. Here, we have developed a strategy using TPP to release dicarboxylates selectively within mitochondria. For this the dicarboxylate is attached to a TPP via a single ester bond which is then cleaved by intra-mitochondrial esterase activity, releasing the dicarboxylate within the organelle. Leaving the second carboxylic acid free also means mitochondrial uptake is dependent on the pH gradient across the inner membrane. To assess this strategy, we synthesized a range of TPP monoesters of the model dicarboxylate, malonate. We then tested their mitochondrial accumulation and ability to deliver malonate to isolated mitochondria, and to cells in vitro and in vivo. A TPP-malonate monoester, TPP11-malonate, in which the dicarboxylate was attached to the TPP via a hydrophobic undecyl link was most effective at releasing malonate within mitochondria in cells and in vivo. Therefore, we have developed a TPP-monoester platform that enables the selective release of bioactive dicarboxylates within mitochondria.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Caldwell, Dr Stuart and Pala, Ms Laura and Hartley, Professor Richard
• Authors: Prag, H. A., Kula-Alwar, D., Pala, L., Caldwell, S. T., Beach, T. E., James, A. M., Saeb-Parsy, K., Krieg, T., Hartley, R. C., and Murphy, M. P.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Molecular Pharmaceutics
• Publisher: American Chemical Society
• ISSN: 1543-8384
• ISSN (Online): 1543-8392
• Published Online: 21 July 2020
• Copyright Holders: Copyright © 2020 American Chemical Society
• First Published: First published in Molecular Pharmaceutics 17(9):3526–3540
• Publisher Policy: Reproduced under a Creative Commons licence
• Data DOI: 10.5525/gla.researchdata.1031

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
172617		Exploring mitochondrial metabolism in health and disease using targeted biological chemistry	Richard Hartley	Wellcome Trust (WELLCOTR)	110158/Z/15/Z	Chemistry