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Biomedical subjects

V A Petrenko

Publications and source records attributed to V A Petrenko.

At least 19 recordsLinked to original sources
PubMed2001

Phage display selection of peptides that affect prostate carcinoma cells attachment and invasion.

BACKGROUND: Prostate cancer-specific proteins must be identified to serve as diagnostic and prognostic markers. Cell surface proteins are especially important, because they have potential utility as diagnostic markers and therapeutic targets. Identification of ligands for these proteins will allow use of these ligands as diagnostic and therapeutic tools and permit the investigation of receptor function. We performed a search for peptide ligands to prostate cancer cell-specific receptors. METHODS: Peptide phage display library was used to isolate specific ligands to LNCaP prostate carcinoma cells receptors. Selected phage and cognate peptides were investigated for their cancer-related functions, such as the ability to interfere with cell adhesion, spreading, motility, and invasion. RESULTS: Phage designated pg35, blocked spreading of LNCaP cells and their derivatives C4-2 and C4-2b. Cognate peptide did not inhibit spreading, but incubation of C4-2 and C4-2b cells with cognate peptide increased their affinity for endothelial cells and invasiveness. In addition, the peptide activates matrix metalloproteinase (MMP)-2 and 9 in C4-2 and C4-2b cells. CONCLUSIONS: These results indicate that identified ligands may play a role in tumorigenicity and metastatic transformation of prostate cancer. To our knowledge, this is the first identification of a functional cancer-specific peptide ligand using the phage display approach.

Amino Acid Sequence↗
PubMed2001

Identifying diagnostic peptides for lyme disease through epitope discovery.

Serum antibodies from patients with Lyme disease (LD) were used to affinity select peptide epitopes from 12 large random peptide libraries in phage display format. The selected peptides were surveyed for reactivity with a panel of positive sera (from LD patients) and negative sera (from subjects without LD), thus identifying 17 peptides with a diagnostically useful binding pattern: reactivity with at least three positive sera and no reactivity with any of the negative sera. The peptides define eight sequence motifs, none of which can be matched convincingly with segments of proteins from Borrelia burgdorferi, the LD pathogen; evidently, then, they are "mimotopes," mimicking natural pathogen epitopes without matching contiguous amino acids of pathogen proteins. Peptides like these could be the basis of a new diagnostic enzyme-linked immunosorbent assay for LD, with sufficient specificity and sensitivity to replace expensive immunoblotting tests that are currently required for definitive serological diagnosis. Moreover, the method used to discover these peptides did not require any knowledge of the pathogen and involved generic procedures that are applicable to almost any infectious disease, including emerging diseases for which no pathogen has yet been identified.

Amino Acid Sequence↗
PubMed2000

Phages from landscape libraries as substitute antibodies.

In 'landscape' phage, as in traditional phage-display constructs, foreign peptides or proteins are fused to coat proteins on the surface of a filamentous phage particle. Unlike conventional constructs, however, each virion displays thousands of copies of the peptide in a repeating pattern, subtending a major fraction of the viral surface. The phage body serves as an interacting scaffold to constrain the peptide into a particular conformation, creating a defined organic surface structure ('landscape') that varies from one phage clone to the next. By testing landscape libraries with three representative antigens (streptavidin from the bacterium Streptomyces avidinii, avidin from chicken egg white and beta-galactosidase from Escherichia coli) we have shown that landscape phages may be used as a new type of substitute antibodies-filaments that can bind protein and glycoprotein antigens with nanomolar affinities and high specificity. In many ways these substitute antibodies are more convenient than their natural immunoglobulin counterparts.

Amino Acid Sequence↗
PubMed1998

Cross-linked filamentous phage as an affinity matrix.

Filamentous phage can be cross-linked to make a hydrophilic aggregate that is pelleted by low-speed centrifugation. The aggregate is stable at near-neutral pHs, and withstands exposure to the acid buffers (pH down to 2.2) that are often used as eluents in immunoaffinity purification. If a peptide epitope is genetically fused to a coat protein on the virion surface, the aggregate serves as an effective affinity matrix for absorbing and affinity-purifying antibodies that bind the peptide. When the peptide epitope is first obtained in this form by selection from large phage display libraries, this ability to fashion an affinity matrix directly from the selected phage represents a significant streamlining of research and development.

Amino Acid Sequence↗
PubMed1996

A library of organic landscapes on filamentous phage.

A billion-clone library of filamentous phage with different surface structures ("landscapes') was generated by fusing random octapeptides to the N-terminus of all 4000 copies of the major coat protein. Such a "landscape library' might include clones exhibiting emergent properties that inhere in the entire surface architecture, not in the peptides by themselves. Because the diverse surface landscapes are displayed on viable phage, they can be surveyed for exceedingly rare functions using microbiological selection methods. Clones with several emergent properties of the sort envisioned were successfully selected, suggesting that landscape libraries have promise as a novel source of nanomaterials with exploitable surface properties.

Amino Acid Sequence↗
PubMed1993

Design of specific immunogens using filamentous phage as the carrier.

Earlier, we developed an expression vector allowing exposure of short peptides on the surface of bacteriophage M13. It was used to obtain a recombinant phage carrying an antigenic determinant of HIV1 p17 Gag protein. Immunoglobulin elicited by immunizing rabbits with the phage reacted with the 17-kDa core protein of the virus and with its polyprotein precursor, p55, on Western blots of HIV1 viral proteins. The results of present experiments may be useful in vaccine development.

Amino Acid Sequence↗
PubMed1993

[Preparation and bacterial expression of a mutant gene for human lymphotoxin].

Using the oligonucleotide directed mutagenesis, a human lymphotoxin (TNF beta) mutant gene lacking 21 N-terminal codons has been obtained. Recombinant plasmid pLT21 for expression of the mutant gene has been constructed. The mutant gene in the plasmid was placed under control of a tandem of constitutive promoters from coliphage T7. A simple procedure for isolation of recombinant protein was developed. The procedure allows to obtain the highly purified biologically active mutant protein with a good yield. During biosynthesis the recombinant protein undergoes a posttranslational processing resulted in the cleavage of N-terminal methionine and leucine residues.

Amino Acid Sequence↗
PubMed1992

Inserting foreign peptides into the major coat protein of bacteriophage M13.

Foreign DNA fragments were inserted into filamentous phage gene VIII to create hybrid B-proteins with foreign sequences in the amino terminus. The hybrid proteins are incorporated into the virions which retain viability and infectivity. Virions with hybrid B-proteins have the same contour length and the same number of B-protein molecules as virions with natural B-proteins. It was shown that for one of hybrid B-proteins the position of the processing site had changed.

Amino Acid Sequence↗
PubMed1991

[Mutagenesis, induced by phosphotriester analogs of oligonucleotides and directed to the cleavage site of double-spiral DNA].

The mutagenic properties of phosphotriester analogues revealed in course of interaction with linearized plasmid DNA were studied. The plasmid-based model system permitting one to test reliably the induced mutations is proposed. The efficiency of mutagenesis was shown to depend on the length of the oligonucleotide-mutagen and the genotype of the transformed Escherichia coli strain. The possible mechanisms involved in mutagenesis are discussed.

Bacteriophages↗
PubMed1989

[Mutagenesis directed by phosphotriester analogs of oligonucleotides: a way to site-specific mutagenesis in vivo].

A new approach is proposed to obtain the directed mutations in the gene under study. The technique is based on using alkylphosphotriester analogues of oligodeoxyribonucleotides as site-specific mutagens. The deletion C in lacZ' gene of bacteriophage M13mpB was obtained by cotransfection of Escherichia coli cells with a mix of DNA and phosphotriester analogues of oligonucleotides.

Base Sequence↗