Nahhas Alaa F, Webster Thomas J
Biochemistry Department, College of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
School of Health Sciences and Biomedical Engineering, Hebei University of Technology, Tianjin, China.
OpenNano. 2022 Jul-Aug;7:100054. doi: 10.1016/j.onano.2022.100054. Epub 2022 Jun 30.
The SARS-CoV-2 Omicron variant is called a "variant of concern" (VOC) which has spread all over the world at a faster rate than even the first SARS-CoV-2 outbreak despite travel restrictions. In order to combat the health consequences from a SARS-CoV-2 Omicron variant infection, the objective of the present study was to develop self-assembled nano peptides to attach to the virus and inhibit its attachment and entry into mammalian cells for replication. For this purpose, two amphipathic peptides containing hydrophobic and hydrophilic peptides and an unnatural amino acid (such as 2-aminoisobutyric acid (U)) were designed to attach to the less mutated virus envelope rather than more frequently mutated S-protein region: NapFFTLUFLTUTEKKKK and NapFFMLUFLMUMEKKKK. These peptides were synthesized using the solid phase peptide synthesis method and were characterized for mammalian cell infection using well-established pseudo virus assays. results showed that the two self-assembled nano peptides significantly inhibited the ability of the SARS-CoV-2 Omicron variant virus to infect mammalian cells and replicate with IC50 values of 0.5 and 360 mg/ml for NapFFTLUFLTUTEKKKK and NapFFMLUFLMUMEKKKK, respectively. Most impressively, 1 mg/ml of NapFFTLUFLTUTEKKKK resulted in a 2 log reduction in pseudovirus replication after just 15 min at a viral load of 10 copies/ml. Results further confirmed that the peptides continued to passivate the SARS-CoV-2 Omicron variant for up to one week and were stable in cell culture media before being added to the virus. Mechanistically, results showed selective binding of the peptides to the SARS-CoV-2 Omicron variant envelop protein over the more frequently mutated spike protein up to one week demonstrating the stability of the peptides. Cytotoxicity studies with fibroblasts also showed no toxicity when exposed to the peptides for 72 h. In summary, the present results strongly suggest that the two peptides developed in this study should be further researched for a wide range of anti-SARS-CoV-2 virus applications, including the present Omicron and future mutations.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）奥密克戎变种被称为“关注变种”（VOC），尽管有旅行限制，但它在全球的传播速度甚至比SARS-CoV-2首次爆发时还要快。为了对抗SARS-CoV-2奥密克戎变种感染带来的健康后果，本研究的目的是开发自组装纳米肽，使其附着于病毒并抑制其附着和进入哺乳动物细胞进行复制。为此，设计了两种含有疏水和亲水肽以及一种非天然氨基酸（如2-氨基异丁酸（U））的两亲性肽，使其附着于变异较少的病毒包膜，而不是变异更频繁的刺突蛋白区域：NapFFTLUFLTUTEKKKK和NapFFMLUFLMUMEKKKK。这些肽采用固相肽合成方法合成，并使用成熟的假病毒检测法对其在哺乳动物细胞感染中的特性进行了表征。结果表明，这两种自组装纳米肽显著抑制了SARS-CoV-2奥密克戎变种病毒感染哺乳动物细胞并进行复制的能力，NapFFTLUFLTUTEKKKK和NapFFMLUFLMUMEKKKK的半数抑制浓度（IC50）值分别为0.5和360mg/ml。最令人印象深刻的是，在病毒载量为10拷贝/ml时，1mg/ml的NapFFTLUFLTUTEKKKK在仅15分钟后就使假病毒复制减少了2个对数。结果进一步证实，这些肽在长达一周的时间内持续使SARS-CoV-2奥密克戎变种失活，并且在添加到病毒之前在细胞培养基中是稳定的。从机制上讲，结果表明这些肽在长达一周的时间内对SARS-CoV-2奥密克戎变种包膜蛋白的结合具有选择性，而不是对变异更频繁的刺突蛋白，这证明了这些肽的稳定性。对成纤维细胞的细胞毒性研究也表明，在接触这些肽72小时后没有毒性。总之，目前的结果强烈表明，本研究中开发的这两种肽应进一步研究其在广泛的抗SARS-CoV-2病毒应用中的作用，包括当前的奥密克戎变种以及未来的变异。
