ABSTRACT

Introduction

The spike (S) of SARS coronavirus 2 (SARS-CoV-2) engages angiotensin-converting enzyme 2 (ACE2) on a host cell to trigger viral-cell membrane fusion and infection. The extracellular region of ACE2 can be administered as a soluble decoy to compete for binding sites on the receptor-binding domain (RBD) of S, but it has only moderate affinity and efficacy. The RBD, which is targeted by neutralizing antibodies, may also change and adapt through mutation as SARS-CoV-2 becomes endemic, posing challenges for therapeutic and vaccine development.

Areas Covered

Deep mutagenesis is a Big Data approach to characterizing sequence variants. A deep mutational scan of ACE2 expressed on human cells identified mutations that increase S affinity and guided the engineering of a potent and broad soluble receptor decoy. A deep mutational scan of the RBD displayed on the surface of yeast has revealed residues tolerant of mutational changes that may act as a source for drug resistance and antigenic drift.

Expert Opinion

Deep mutagenesis requires a selection of diverse sequence variants; an in vitro evolution experiment that is tracked with next-generation sequencing. The choice of expression system, diversity of the variant library and selection strategy have important consequences for data quality and interpretation.

中文翻译：

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COVID-19研究中的深层诱变：蛋白质组学领域的技术概述

摘要

介绍

SARS冠状病毒2（SARS-CoV-2）的尖峰（S）与宿主细胞上的血管紧张素转化酶2（ACE2）结合，触发病毒细胞膜融合和感染。ACE2的细胞外区域可以作为可溶性诱饵来竞争，以竞争S的受体结合域（RBD）上的结合位点，但仅具有中等的亲和力和功效。随着SARS-CoV-2流行，以中和抗体为目标的RBD也可能通过突变而改变和适应，这为治疗和疫苗开发提出了挑战。

覆盖区域

深度诱变是表征序列变异体的大数据方法。在人类细胞上表达的ACE2的深层突变扫描确定了增加S亲和力的突变，并指导了有效而广泛的可溶性受体诱饵的工程设计。对酵母表面上显示的RBD进行的深层突变扫描显示，其残基能够耐受突变变化，而这些变化可能会成为耐药性和抗原漂移的来源。

专家意见

深度诱变需要选择各种序列变体。下一代测序跟踪的体外进化实验。表达系统的选择，变体文库的多样性和选择策略对数据质量和解释具有重要影响。