Total Chemical Synthesis of the SARS‐CoV‐2 Spike Receptor‐Binding Domain

• Published in: Chemistry : a European journal 2024-01, Vol.30 (3), p.e202302969-n/a
• Main Authors: Kar, Abhisek, Jana, Mrinmoy, Malik, Vishal, Sarkar, Arighna, Mandal, Kalyaneswar
• Format: Article
• Language: English
• Subjects: Angiotensin-Converting Enzyme 2 - metabolism; Binding; chemical protein synthesis; Chemical synthesis; Chemistry; Coronaviruses; COVID-19; Enantiomers; Humans; native chemical ligation; Peptide synthesis; Protein Binding; Proteins; Public health; Receptors; SARS-CoV-2 - metabolism; SARS-CoV2; Severe acute respiratory syndrome; Severe acute respiratory syndrome coronavirus 2; Solid phases; Spike Glycoprotein, Coronavirus - chemistry; Spike protein; spike RBD; Therapeutic applications; Viral diseases
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202302969

SARS‐CoV‐2 and its global spread have created an unprecedented public health crisis. The spike protein of SARS‐CoV‐2 has gained significant attention due to its crucial role in viral entry into host cells and its potential as both a prophylactic and a target for therapeutic interventions. Herein, we report the first successful total synthesis of the SARS‐CoV‐2 spike protein receptor binding domain (RBD), highlighting the key challenges and the strategies employed to overcome them. Appropriate utilization of advanced solid phase peptide synthesis and cutting‐edge native chemical ligation methods have facilitated the synthesis of this moderately large protein molecule. We discuss the problems encountered during the chemical synthesis and approaches taken to optimize the yield and the purity of the synthetic protein molecule. Furthermore, we demonstrate that the chemically synthesized homogeneous spike RBD efficiently binds to the known mini‐protein binder LCB1. The successful chemical synthesis of the spike RBD presented here can be utilized to gain valuable insights into SARS‐CoV‐2 spike RBD biology, advancing our understanding and aiding the development of intervention strategies to combat future coronavirus outbreaks. The modular synthetic approach described in this study can be effectively implemented in the synthesis of other mutated variants or enantiomer of the spike RBD for mirror‐image drug discovery. An elegant total chemical synthesis route has been developed for SARS‐CoV‐2 spike‐RBD. Leveraging a multi‐segment convergent native chemical ligation strategy, this innovative approach holds immense promise in advancing the development of effective intervention strategies against SARS‐CoV‐2. The highly efficient chemical synthesis method outlined here can be directly applied to the synthesis of other mutated variants or the mirror‐image of the spike RBD for screening against peptide/protein‐based library.