Inhibition Efficiency of Cyclic and Bi-cyclic Temporin L Analogues against the Main Protease of SARS-CoV-2
Disciplines
Biochemistry | Other Immunology and Infectious Disease | Virology
Abstract (300 words maximum)
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants are responsible for the devastating coronavirus disease 2019 (COVID-19) with more than seven million deaths since 2019. SARS-CoV-2 is a single stranded RNA virus which encodes two nonstructural polyproteins and several structural & accessory proteins. Non-structural proteins are initially divided into two polypeptides and these need to be cleaved into single functional units to assemble into new viruses. SARS CoV-2 contains two enzymes responsible for the viral replication such as Papain-like protease (PLpro) and Main protease (Mpro). Since Mpro cleaves more sites in the polyproteins than PLpro, the inhibition of this viral protease enzyme effectively interrupts the replication of the virus. Although small-molecule drugs have showed promising results against Mpro, peptide therapeutics are more target specific and show lesser adverse effects. Cyclization of side chains or backbones can reduce proteolytic instability. Previous studies from our group showed that Temporin L could effectively inhibit the main protease, however, this peptide showed a shorter half-life. The overall goal is to develop cyclic analogues of Temporin L and investigate their inhibition efficiency and improve the serum half-life. Initially, linear Temporin L analogue containing two (2CTLP) and three cysteines (3CTLP1 and 3CTLP2) were synthesized by solid phase peptide synthesis. Cyclic peptides from 2CTLP were conducted by using Dimethyl Sulfoxide (DMSO), Hexafluorobenzene (C6F6), α,α’-Dibromo-P-Xylene and α,α’-Dichloro-P-Xylene. Bicyclic peptides were synthesized by incorporating 1,3,5-Triacryloylhexahydro-1,3,5-Triazine (TATA) and 1,3,5-Tris (Bromomethyl) Benzene (TBMB). Synthesis of cyclic peptides was confirmed by mass spectrometer. Bi-cyclic analogues of 3CTLP2 using TATA showed inhibition efficiency (IC50 4.00 µM) which was lower and better than other cyclic and bicyclic peptides. Future studies will be directed to further investigation of their serum stability, enzymatic stability, cell viability and binding efficacy.
Academic department under which the project should be listed
CSM - Chemistry and Biochemistry
Primary Investigator (PI) Name
Mohammad A. Halim
Inhibition Efficiency of Cyclic and Bi-cyclic Temporin L Analogues against the Main Protease of SARS-CoV-2
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants are responsible for the devastating coronavirus disease 2019 (COVID-19) with more than seven million deaths since 2019. SARS-CoV-2 is a single stranded RNA virus which encodes two nonstructural polyproteins and several structural & accessory proteins. Non-structural proteins are initially divided into two polypeptides and these need to be cleaved into single functional units to assemble into new viruses. SARS CoV-2 contains two enzymes responsible for the viral replication such as Papain-like protease (PLpro) and Main protease (Mpro). Since Mpro cleaves more sites in the polyproteins than PLpro, the inhibition of this viral protease enzyme effectively interrupts the replication of the virus. Although small-molecule drugs have showed promising results against Mpro, peptide therapeutics are more target specific and show lesser adverse effects. Cyclization of side chains or backbones can reduce proteolytic instability. Previous studies from our group showed that Temporin L could effectively inhibit the main protease, however, this peptide showed a shorter half-life. The overall goal is to develop cyclic analogues of Temporin L and investigate their inhibition efficiency and improve the serum half-life. Initially, linear Temporin L analogue containing two (2CTLP) and three cysteines (3CTLP1 and 3CTLP2) were synthesized by solid phase peptide synthesis. Cyclic peptides from 2CTLP were conducted by using Dimethyl Sulfoxide (DMSO), Hexafluorobenzene (C6F6), α,α’-Dibromo-P-Xylene and α,α’-Dichloro-P-Xylene. Bicyclic peptides were synthesized by incorporating 1,3,5-Triacryloylhexahydro-1,3,5-Triazine (TATA) and 1,3,5-Tris (Bromomethyl) Benzene (TBMB). Synthesis of cyclic peptides was confirmed by mass spectrometer. Bi-cyclic analogues of 3CTLP2 using TATA showed inhibition efficiency (IC50 4.00 µM) which was lower and better than other cyclic and bicyclic peptides. Future studies will be directed to further investigation of their serum stability, enzymatic stability, cell viability and binding efficacy.
