title: Inhibition of the hepatitis C virus NS3 protease activity by Fv fragment of antibody 8D4.
abstract: An antibody variable domain fragment (Fv) is a candidate for a specific inhibitor of the hepatitis C virus (HCV) NS3 protease. Here we report the functional characterization of the Fv of antibody 8D4, which is specific for the active site of the HCV NS3 protease domain. The variable fragments of 8D4 in the forms of Fv and scFv (VH-(G(4)S)(3)-VL) were expressed as insoluble fractions in the periplasm of Escherichia coli, and were subsequently solubilized, purified under denaturing conditions, and refolded. The Fv had an inhibition profile almost identical to that of the parent IgG, with an IC(50) of 71.3 nM, whereas the scFv had a greatly decreased affinity to NS3 and was the same as the isolated VH fragment. To date, this is the first report of an antibody Fv fragment specific for the HCV NS3 protease domain, aimed at designing potent protease inhibitors and antiviral drugs.
authors.affiliation: Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kasai
authors.forename: K
authors.initials: K
authors.lastname: Tsumoto
authors.forename: S
authors.initials: S
authors.lastname: Niwa
authors.forename: S
authors.initials: S
authors.lastname: Misawa
authors.forename: T
authors.initials: T
authors.lastname: Ueno
authors.forename: H
authors.initials: H
authors.lastname: Hayashi
authors.forename: I
authors.initials: I
authors.lastname: Kumagai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004274:DNA, Recombinant / Q000235:genetics / Q000302:isolation & purification; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000235:genetics; D005786:Gene Expression Regulation; D016174:Hepacivirus / Q000201:enzymology*; D007128:Immunoglobulin Fragments / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007147:Immunoglobulin Light Chains / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000737:chemistry / Q000235:genetics; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D011485:Protein Binding; D017510:Protein Folding; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D017361:Viral Nonstructural Proteins / Q000037:antagonists & inhibitors* / Q000276:immunology / Q000378:metabolism; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
chemical_list: D000911:Antibodies, Monoclonal; D018076:DNA, Complementary; D004274:DNA, Recombinant; D007128:Immunoglobulin Fragments; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; C055966:immunoglobulin Fv