title: Allosteric inhibition of aminopeptidase N functions related to tumor growth and virus infection.
abstract: Cell surface aminopeptidase N (APN) is a membrane-bound ectoenzyme that hydrolyzes proteins and peptides and regulates numerous cell functions. APN participates in tumor cell expansion and motility, and is a target for cancer therapies. Small drugs that bind to the APN active site inhibit catalysis and suppress tumor growth. APN is also a major cell entry receptor for coronavirus, which binds to a region distant from the active site. Three crystal structures that we determined of human and pig APN ectodomains defined the dynamic conformation of the protein. These structures offered snapshots of closed, intermediate and open APN, which represent distinct functional states. Coronavirus envelope proteins specifically recognized the open APN form, prevented ectodomain progression to the closed form and substrate hydrolysis. In addition, drugs that bind the active site inhibited both coronavirus binding to cell surface APN and infection; the drugs probably hindered APN transition to the virus-specific open form. We conclude that allosteric inhibition of APN functions occurs by ligand suppression of ectodomain motions necessary for catalysis and virus cell entry, as validated by locking APN with disulfides. Blocking APN dynamics can thus be a valuable approach to development of drugs that target this ectoenzyme.
authors.affiliation: Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: César
authors.initials: C
authors.lastname: Santiago
authors.affiliation: Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.|Department of Biotechnology, Institute of Engineering and Technology, Mangalayatan University, 33rd Milestone, Beswan, Aligarh, UP, India-202145.
authors.forename: Gaurav
authors.initials: G
authors.lastname: Mudgal
authors.affiliation: Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.|INSERM, Aix-Marseille Université, CNRS, AFMB UMR 7257, 163 avenue de Luminy, 13288 Marseille, France.
authors.forename: Juan
authors.initials: J
authors.lastname: Reguera
authors.affiliation: Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.|Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga LV-1006, Latvia.
authors.forename: Rosario
authors.initials: R
authors.lastname: Recacha
authors.affiliation: Laboratoire de Chimie Organique et Bioorganique, Ecole Nationale Supérieure de Chimie Mulhouse, Université Haute-Alsace, 68093 Mulhouse, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Albrecht
authors.affiliation: Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Enjuanes
authors.affiliation: Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Casasnovas
mesh_terms: D000494:Allosteric Regulation / Q000187:drug effects; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D055162:Biocatalysis / Q000187:drug effects; D018826:CD13 Antigens / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D016466:CHO Cells; D020134:Catalytic Domain; D049109:Cell Proliferation / Q000187:drug effects; D017934:Coronavirus / Q000187:drug effects / Q000502:physiology*; D018352:Coronavirus Infections / Q000473:pathology* / Q000821:virology*; D006224:Cricetinae; D003412:Cricetulus; D004220:Disulfides / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D009369:Neoplasms / Q000473:pathology*; D000072417:Protein Domains; D034421:Sus scrofa
chemical_list: D000970:Antineoplastic Agents; D004220:Disulfides; D018826:CD13 Antigens