Identification and Benchmarking of Myokinasib-II as a Selective and Potent Chemical Probe for Exploring MLCK1 Inhibition

• Published in: ACS chemical biology 2024-10, Vol.19 (10), p.2165-2175
• Main Authors: Kumar, Gautam, Agarwala, Prema Kumari, Srivatsav, Aswin T., Ravula, Ashok, Ashmitha, G., Balakrishnan, Sreenath, Kapoor, Shobhna, Narayan, Rishikesh
• Format: Article
• Language: English
• ISSN: 1554-8929; 1554-8937; 1554-8937
• DOI: 10.1021/acschembio.4c00336

Deciphering the functional relevance of every protein is crucial to developing a better (patho)­physiological understanding of human biology. The discovery and use of quality chemical probes propel exciting developments for developing drugs in therapeutic areas with unmet clinical needs. Myosin light-chain kinase (MLCK) serves as a possible therapeutic target in a plethora of diseases, including inflammatory diseases, cancer, etc. Recent years have seen a substantial increase in interest in exploring MLCK biology. However, there is only one widely used MLCK modulator, namely, ML-7, that too with a narrow working concentration window and high toxicity profile leading to limited insights. Herein, we report the identification of a potent and highly selective chemical probe, Myokinasib-II, from the synthesis and structure–activity relationship studies of a focused indotropane-based compound collection. Notably, it is structurally distinct from ML-7 and hence meets the need for an alternative inhibitor to study MLCK biology as per the recommended best practices. Moreover, our extensive benchmarking studies demonstrate that Myokinasib-II displays better potency, better selectivity profile, and no nonspecific interference in relevant assays as compared to other known MLCK inhibitors.