MODIFIED PHEUMOLYSINE RECOMBINANT PLASMID, METHOD OF PRODUCING MODIFIED PHEUMOLYSINE AND VACCINE Russian patent published in 1998 - IPC

FIELD: gene engineering, more particularly preparation of modified pneumolysine and manufacture of vaccine based thereon. SUBSTANCE: modified pneumolysine is produced by oligonucleotide directed mutagenesis. Modified wild-type pneumolysine gene is then expressed in bacteria E.Coli. Modified pneumolysine has certain amino acid sequence. One or more amino acid replacements, deletions or blocking mutations are made in sites 427-437, 367-398 and 257-297 of said amino acid sequence. Recombinant plasmid that determines synthesis of modified pneumolysine is constructed by vector pKK233-2 and comprises ampicillin- and tetracycline-resistant genes. Isopropyl β-D- thiogalactopyranoside regulated promoter trc. Ribosom lac binding site adjacent to initiation codon ATG. Restriction sites for endonulceases Pst I and Hind III. Modified pneumolysine gene cloned into NCO I site which has certain sequence of nucleotides. Vaccine capable of inducing immune response in animals comprises antigen from modified pneumolysine. EFFECT: improved properties of the vaccine. 7 cl