NeoCoV, a coronavirus strain related to MERS-CoV found in bats (NeoCoV is not a new variant of SARS-CoV-2, the human coronavirus strain responsible for COVID-19 pandemic) has been reported to be the first case of a MERS-CoV variant using ACE2. NeoCoV has potential of human emergence with both high fatality and transmission rate.
NeoCoV ialah strain yang berkaitan dengan MERS-CoV yang menggunakan kelawar Ace 2 reseptor untuk kemasukan dan jangkitan ke dalam sel kelawar. Walau bagaimanapun, ketegangan daripada MERS-CoV menggunakan reseptor DPP4 untuk kemasukan selular. Adalah penting untuk ambil perhatian bahawa NeoCoV bukanlah varian baharu SARS-CoV-2 yang telah menyebabkan wabak di seluruh dunia sejak kemunculannya pada November 2019.
This article shows that NeoCoV and its close relative PDF-2180-CoV is able to efficiently bind to ACE 2 receptors in bat, but bind less favourably to human ACE 2 receptors. Studies using cryo-electron microscopy revealed a distinct virus-ACE 2 binding surface in case of binding of NeoCoV and PDF-2180-CoV to ACE 2 receptors. A molecular determinant implicates Asp 338 residue, that prevents NeoCoV from binding to human ACE 2 receptor. In addition, a T510F mutation in the receptor binding motif of NeoCoV causes it to efficiently bind human ACE 2 receptor.
Given the high fatality rate of 35% associated with MERS-CoV related virus derived from Beta CoV lineage, the NeoCoV could pose a potential threat to emergence of a high transmissible strain of NeoCoV and PDF-2180-CoV (upon gaining the T510F mutation due to antigenic drift) that can cause infection and mortality in humans, far worse than the current pandemic. Antigenic drift refers to random genetic mutasi yang menyebabkan perubahan dalam protein soya struktur, dengan itu mengubah keupayaan protein untuk mengikat kepada reseptor tertentu. Selain itu, jangkitan yang disebabkan oleh mutasi T510F NeoCoV, tidak boleh dineutralkan silang oleh antibodi yang menyasarkan SARS-CoV-2 atau MERS-CoV.
The entire global community hopes that the mutation in NeoCoV and PDF-2180-CoV that causes it to efficiently bind to human ACE 2 receptor, remains a laboratory study to understand the virulence of these virus, and it doesn’t become a case of zoonotic transmission from bats to humans, creating another worldwide chaos.
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sumber:
Yan H., et al 2022. Saudara terdekat MERS-CoV dalam kelawar menggunakan ACE2 sebagai reseptor berfungsi mereka. Pracetak bioRxiv. Disiarkan pada 25 Januari 2022. DOI: https://doi.org/10.1101/2022.01.24.477490
