[Protein engineering of uridine phosphorylase from Escherichia coli K-12. II. Comparative study of hybrid and mutant forms of uridine phosphorylases].

Genes for hybrid uridine phosphorylases (UPases) consisting of fragments of amino acid sequences of UPases from Escherichia coli and Salmonella typhimurium were constructed. Producing strains of the corresponding proteins were genetically engineered. Mutant forms of the E.

[Design of the human tumor-associated VNTR(Muc1) antigen gene, fused with streptavidin, its expression in Escherichia coli. Study of properties of the hybrid protein].

A gene of human tumor-associated antigen VNTR(MUC1) bound to streptavidin, an expression plasmid, and a highly effective hybrid protein-producing strain were constructed. It was shown that the streptavidin leader peptide ensures an effective secretion of the hybrid protein into the periplasmic space of Escherichia coli cells. The hybrid protein was isolated in a homogeneous state and its immunogenic properties were studied.

[Cloning transforming genes from human papillomavirus type 18].

Nucleotide sequences of type 18 human papilloma virus genes E6 and E7 inserted in human DNA cloned from cervical tumor are determined. The resultant sequences are compared to the prototype variant. Five point mutations not leading to replacement of amino acid residues in polypeptide chain and 1 substituting the amino acid in codon 129 are detected in gene E6 sequence.

Cloning of E6 and E7 genes of human papilloma virus type 18 and transformation potential of E7 gene and its mutants.

E6 and E7 genes of human papilloma virus type 18 have been subcloned from plasmid pC7, carrying an insert of DNA from squamous cell carcinoma of cervix. Both genes in comparison to prototype variant contain one mutation that changes asparagine to leucine. In the case of E6 gene this mutation is mapped in codon 129, in the case of E7 the same change AAC to AAA mapped in codon 92.

[Cloning of streptavidin gene from Streptomyces avidinii and its expression in Escherichia coli. Secretion of streptavidin by E. coli cells].

The streptavidin gene from Streptomyces avidinii was cloned, an expression plasmid constructed, and a highly effective strain producer of streptavidin created. It was shown that the leader peptide of streptavidin ensures the effective secretion of this protein into the periplasmic space of Escherichia coli cells. The degradation site of the leader peptide was detected.