Molecular Docking Simulations of Protoporphyrin IX, Chlorin e6, and Methylene Blue for Target Proteins of Viruses Causing Skin Lesions: Monkeypox and HSV

Background: The replication of monkeypox in the skin is critical to understanding its pathogenesis and spread. p37, a highly conserved 37 kDa peripheral membrane protein encoded by the F13L gene in Orthopoxvitidae is a validated target for anti-poxviral medication like tecovirimat, the first FDA-approved anti-poxviral drug that was approved in 2018. The detailed recognition mechanism of tecovirimat on p37 of monkeypox has not been fully clarified. As p37, HSV-1 gD and HSV-2 gD proteins of HSV are viral envelope glycoproteins identified as ligands for the human nectin-1 as a functional receptor of permissive cells. The use of non-damaging light for microbial inactivation (MI) has been documented for different virus like HSV, where photosensitizers (PSs) are used as lightresponsive agents which could generate antiviral responses primarily by oxidation. In addition, some PSs could elicit antiviral responses in a light-independent way by interacting within the viral-cell recognition sites. Objective: This paper aims to evaluate the formation of complexes between the latest structural data available on the range of monkeypox and HSV-1/2 envelope proteins with the approved PSs protoporphyrin IX, chlorin e6, and methylene blue. Methods: Ligands and receptors preparation, and molecular docking analyses were performed with Chimera and the Autodock Vina Software. Molecular docking and molecular dynamics simulation (MD) analyses for a 100 ns trajectory were also performed for the p37 – Methylene blue complex. Results: PSs studies were found to form complexes into the patch regions of recognition between HSV-1/2 gD and human receptors, while MB was found to form a complex with the p37 protein into de pocket region where tecovirimat acts. MD simulation showed stability in the interaction of MB with the pocket region of the p37 protein. Conclusion: The molecular mechanisms of potential dual antiviral activity for these complexes were clarified showing that MI with the use of these PSs could be further evaluated for viral skin lesions produced by monkeypox and HSV.