title: A mutant streptokinase lacking the C-terminal 42 amino acids is less reactive with preexisting antibodies in patient sera.
abstract: Streptokinase (SK) is an efficacious thrombolytic drug for the treatment of myocardial infarction. Because of its immunogenicity, patients receiving SK therapy develop high anti-SK antibody (Ab) titers, which might provoke severe allergic reactions and neutralize SK activity. In this report we studied the reactivity of a synthetic 42-residue peptide resembling SKC-2 C-terminus with patient sera. SKC-2(373-414) peptide was recognized by 39 and 64% of patients, before and after SKC-2 therapy, respectively. An SKC-2 deletion mutant (mut-C42), lacking the same 42 C-terminal residues, was constructed and expressed in Escherichia coli. Recognition of mut-C42 by preexisting Abs from patient sera was 51 and 68% of reactivity to SKC-2, as assessed by direct binding and competition assays, respectively. For most of the patients, mut-C42-neutralizing activity titer (NAT) significantly decreased with respect to SKC-2-NAT. This study opens the possibility of producing a less immunogenic variant of SK, which could constitute a preferred alternative for thrombolytic therapy.
authors.affiliation: Division of Pharmaceutical, Centro de Ingeniería Genética y Biotecnología, Havana, Cuba. Isis@cigb.edu.cu
authors.forename: I
authors.initials: I
authors.lastname: Torréns
authors.forename: A G
authors.initials: AG
authors.lastname: Ojalvo
authors.forename: A
authors.initials: A
authors.lastname: Seralena
authors.forename: E
authors.initials: E
authors.lastname: Pupo
authors.forename: V
authors.initials: V
authors.lastname: Lugo
authors.forename: R
authors.initials: R
authors.lastname: Páez
mesh_terms: D000485:Allergens / Q000737:chemistry / Q000276:immunology; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology*; D000942:Antigens, Bacterial / Q000737:chemistry / Q000276:immunology; D001667:Binding, Competitive; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D016056:Immunodominant Epitopes / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D009203:Myocardial Infarction / Q000188:drug therapy / Q000276:immunology; D009500:Neutralization Tests; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D017384:Sequence Deletion / Q000235:genetics*; D013300:Streptokinase / Q000737:chemistry* / Q000235:genetics / Q000276:immunology* / Q000627:therapeutic use; D015912:Thrombolytic Therapy
chemical_list: D000485:Allergens; D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D016056:Immunodominant Epitopes; D010446:Peptide Fragments; D011994:Recombinant Proteins; D013300:Streptokinase