Ana Simovic , Mirjana Radomirovic , Nikola Gligorijevic , Milos Milcic , Masa Bicanin , Simeon Minic , Marijana Stojanovic , Dragana Stanic-Vucinic , Tanja Cirkovic Velickovic
{"title":"食物来源的生物活性色素藻蓝胆素与SARS-CoV-2刺突蛋白共价和非共价结合,影响其构象和功能","authors":"Ana Simovic , Mirjana Radomirovic , Nikola Gligorijevic , Milos Milcic , Masa Bicanin , Simeon Minic , Marijana Stojanovic , Dragana Stanic-Vucinic , Tanja Cirkovic Velickovic","doi":"10.1016/j.abb.2025.110475","DOIUrl":null,"url":null,"abstract":"<div><div>Phycocyanobilin (PCB), tetrapyrrole chromophore of Spirulina phycocyanin, is bilirubin analog and weak thiol-modifying agent. SARS-CoV-2 spike protein (SP) has bilirubin binding pocket, lacks free sulfhydryl, but it has two pairs of functionally important semi-stable disulfides reactive towards thiol-modifying agents. We investigated covalent and noncovalent binding of PCB to SP and its receptor-binding domain (RBD) and impact of covalent PCB conjugation to RBD on structure and binding to human angiotensin-converting enzyme 2 (ACE-2). PCB shows high-affinity for SP (Ka = 2.1 × 10<sup>7</sup> M<sup>−1</sup>), moderate-affinity for RBD (Ka = 8.4 × 10<sup>4</sup> M<sup>−1</sup>) and binds covalently to SP and RBD in reaction involving thiols. PCB binding alters RBD conformation. Molecular docking identified two binding sites of PCB to SP, bilirubin/biliverdin binding site and hydrophobic pocket of RBD in vicinity of Cys432, preferential target for covalent binding in <em>in silico</em> covalent docking of PCB to RBD. Redox proteomics mapped reactive Cys432, Cys391 and Cys525 in RBD. PCB-modified RBD exhibited reduced ability to bind to ACE-2. This is the first study demonstrating PCB reactivity towards semi-stable disulfides of proteins lacking free sulfhydryl groups. PCB may affect functionality and structure of SP and its RBD by noncovalent and covalent binding.</div></div>","PeriodicalId":8174,"journal":{"name":"Archives of biochemistry and biophysics","volume":"770 ","pages":"Article 110475"},"PeriodicalIF":3.8000,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Food-derived bioactive pigment phycocyanobilin binds to SARS-CoV-2 spike protein both covalently and noncovalently affecting its conformation and functionality\",\"authors\":\"Ana Simovic , Mirjana Radomirovic , Nikola Gligorijevic , Milos Milcic , Masa Bicanin , Simeon Minic , Marijana Stojanovic , Dragana Stanic-Vucinic , Tanja Cirkovic Velickovic\",\"doi\":\"10.1016/j.abb.2025.110475\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Phycocyanobilin (PCB), tetrapyrrole chromophore of Spirulina phycocyanin, is bilirubin analog and weak thiol-modifying agent. SARS-CoV-2 spike protein (SP) has bilirubin binding pocket, lacks free sulfhydryl, but it has two pairs of functionally important semi-stable disulfides reactive towards thiol-modifying agents. We investigated covalent and noncovalent binding of PCB to SP and its receptor-binding domain (RBD) and impact of covalent PCB conjugation to RBD on structure and binding to human angiotensin-converting enzyme 2 (ACE-2). PCB shows high-affinity for SP (Ka = 2.1 × 10<sup>7</sup> M<sup>−1</sup>), moderate-affinity for RBD (Ka = 8.4 × 10<sup>4</sup> M<sup>−1</sup>) and binds covalently to SP and RBD in reaction involving thiols. PCB binding alters RBD conformation. Molecular docking identified two binding sites of PCB to SP, bilirubin/biliverdin binding site and hydrophobic pocket of RBD in vicinity of Cys432, preferential target for covalent binding in <em>in silico</em> covalent docking of PCB to RBD. Redox proteomics mapped reactive Cys432, Cys391 and Cys525 in RBD. PCB-modified RBD exhibited reduced ability to bind to ACE-2. This is the first study demonstrating PCB reactivity towards semi-stable disulfides of proteins lacking free sulfhydryl groups. PCB may affect functionality and structure of SP and its RBD by noncovalent and covalent binding.</div></div>\",\"PeriodicalId\":8174,\"journal\":{\"name\":\"Archives of biochemistry and biophysics\",\"volume\":\"770 \",\"pages\":\"Article 110475\"},\"PeriodicalIF\":3.8000,\"publicationDate\":\"2025-05-20\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Archives of biochemistry and biophysics\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0003986125001882\",\"RegionNum\":3,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"BIOCHEMISTRY & MOLECULAR BIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Archives of biochemistry and biophysics","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0003986125001882","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
Food-derived bioactive pigment phycocyanobilin binds to SARS-CoV-2 spike protein both covalently and noncovalently affecting its conformation and functionality
Phycocyanobilin (PCB), tetrapyrrole chromophore of Spirulina phycocyanin, is bilirubin analog and weak thiol-modifying agent. SARS-CoV-2 spike protein (SP) has bilirubin binding pocket, lacks free sulfhydryl, but it has two pairs of functionally important semi-stable disulfides reactive towards thiol-modifying agents. We investigated covalent and noncovalent binding of PCB to SP and its receptor-binding domain (RBD) and impact of covalent PCB conjugation to RBD on structure and binding to human angiotensin-converting enzyme 2 (ACE-2). PCB shows high-affinity for SP (Ka = 2.1 × 107 M−1), moderate-affinity for RBD (Ka = 8.4 × 104 M−1) and binds covalently to SP and RBD in reaction involving thiols. PCB binding alters RBD conformation. Molecular docking identified two binding sites of PCB to SP, bilirubin/biliverdin binding site and hydrophobic pocket of RBD in vicinity of Cys432, preferential target for covalent binding in in silico covalent docking of PCB to RBD. Redox proteomics mapped reactive Cys432, Cys391 and Cys525 in RBD. PCB-modified RBD exhibited reduced ability to bind to ACE-2. This is the first study demonstrating PCB reactivity towards semi-stable disulfides of proteins lacking free sulfhydryl groups. PCB may affect functionality and structure of SP and its RBD by noncovalent and covalent binding.
期刊介绍:
Archives of Biochemistry and Biophysics publishes quality original articles and reviews in the developing areas of biochemistry and biophysics.
Research Areas Include:
• Enzyme and protein structure, function, regulation. Folding, turnover, and post-translational processing
• Biological oxidations, free radical reactions, redox signaling, oxygenases, P450 reactions
• Signal transduction, receptors, membrane transport, intracellular signals. Cellular and integrated metabolism.