1,721,065 research outputs found
Phage display of antibody fragments
No full textIn recent years, phage display of peptides and proteins has become a very popular method in oncology, immunology, protein engineering and ligand-receptor studies among others. Antibody fragments, as Fabs or single chain Fv, have been among the first proteins to be displayed on the surface of a filamentous bacteriophage with a procedure initially described in 1990 by McCafferty et al. (Nature, 348, 552-554). From that time, molecular biology techniques have allowed the creation of large repertoires of antibody fragments from antibody V genes, bypassing hybrydoma technology and even immunisation. A large number of phage antibody libraries, from which molecules of the desired functional properties can be rapidly selected, have been built and distributed in many laboratories world-wide. Antibody fragments recovered from phage libraries generally show moderate binding strength; with different systems of biopanning binders can be obtained with dissociation constant ranged between 10-(5) to 10-(8) M. Nevertheless, antibody fragments can be furtherly modified to improve affinity or avidity, respectively by mutating crucial residues of complementarity determining regions or by increasing the number of binding sites making dimeric, trimeric or multimeric molecules. Here, we summarise the latest progress in this field, with particular reference to applications of scFv in the diagnosis and therapy of solid tumours and in the molecular mimicry of viral antigens and membrane receptors. In fact, the production of artificial protein epitopes by phage antibodies is becoming a valid system to overcome problems caused by difficult cloning and low expression of particular recombinant protein
COMPOSTI ANTI TNF-ALPHA E LORO USI
No full textLa presente invenzione riguarda un peptide, i suoi derivati multimerici, relativa composizione farmaceutica e loro usi in terapia, in particolare per inibire l’attività del TNF-alpha
Phage display and colony filter screening for high-throughput selection of antibody libraries
No full textDuring the last 12 years, antibody combinatorial libraries have provided a new approach for the construction and production of reagents and drugs based on the human monoclonal antibodies. Studies employing antibodies or antibody mimics have become an important part of the explosive growth of proteomics. This places tremendous emphasis on the new approaches for faster library screening, improved methods of selection and evaluation of novel applications. The phage display system, together with its variants of ribosome and bacterial display, is the most extensively used method for the rapid screening of large antibody libraries. However, in the last two years the need to improve selection methods together with a complex patent situation regarding the phage display system, has also directed research towards the possibility of performing antibody selection by colony filter screening. Here, we summarise the results obtained by these different methods of selection comparing their efficacy and advantage
Antimicrobial peptide, branched forms thereof, and their use in the treatment of bacterial infections
Full text linkThe instant invention refers to an antibacterial peptide with all aminoacids in D-configuration, possessing strong
antimicrobial activity against Gram-negative and Gram-positive bacteria and Candida strains. The peptide can be in linear form or
multimerised on a skeleton of polyacrylamide, of dextrane units or on a skeleton of ethylene glycol units. The peptide is resistant
to proteolysis especially when synthesized in the tetra-branched form where identical peptide sequences are linked together by an
appropriate molecular scaffold
Branched peptides as therapeutics
No full textThe concept of ‘magic bullet’, initially ascribed to immunoglobulins by Paul Ehrlich at the beginning of the
20th century and strengthened by the hybridoma technology of Kohler and Milstein in the mid 70s, can nowadays be attributed
to different target-specific molecules, such as peptides. This attribution is increasingly valid in light of the explosion
of new technologies for peptide library construction and screening, not to mention improvements in peptide synthesis
and conjugation and in-vivo peptide stability, which make peptide molecules specific bullets for targeting pathological
markers and pathogens. Today, hundreds of peptides are being developed and dozens are in clinical trials for a variety of
diseases, demonstrating that the general reluctance towards peptide drugs that existed a decade ago has now been overcome.
In spite of this progress, the development of new peptide drugs has largely been limited by their short half-life.
Branched peptides such as Multiple Antigen Peptides (MAPs) were invented in the 80s by Tam [Tam, J.P., (1998) Proc.
Natl. Acad. Sci. USA, 85, 5409] and have been extensively tested to reproduce single epitopes to stimulate the immune
system for new vaccine discovery. In our lab we discovered that MAP molecules acquire strong resistance to proteases
and peptidases. This resistance renders MAPs very stable and thus suitable for drug development. Here we report our experience
with several MAP molecules in different biotechnological applications ranging from antimicrobial and anti toxin
peptides to peptides for tumor targeting
Oligo-branched peptides for tumor targeting: From magic bullets to magic forks
No full textBACKGROUND: Selective targeting of tumor cells is the final goal of research and drug discovery for cancer diagnosis, imaging and therapy. After the invention of hybridoma technology, the concept of magic bullet was introduced into the field of oncology, referring to selective killing of tumor cells, by specific antibodies. More recently, small molecules and peptides have also been proposed as selective targeting agents.
OBJECTIVE/METHODS: We analyze the state of the art of tumor-selective agents that are presently available and tested in clinical settings. A novel approach based on 'armed' oligo-branched peptides as tumor targeting agents, is discussed and compared with existing tumor-selective therapies mediated by antibodies, small molecules or monomeric peptides.
RESULTS/CONCLUSIONS: Oligo-branched peptides could be novel drugs that combine the advantages of antibodies and small molecules
Solubility improvement of an anthrax toxin peptide inhibitor by rational aminoacid randomization
No full textWe previously described a potent anthrax toxin inhibitor, based on a phage-library-selected peptide sequence, synthesized as a tetra-branched molecule on a lysine core and further modified for improvement of activity [Pini et al., Biochem. J., 2006, 395, 157]. This branched peptide had very low solubility because of several hydrophobic residues in the peptide sequence. This complicated molecule purification and manufacturing. Here we report a rational modification of the peptide sequence, obtained by construction and selection of several mini libraries of branched peptides, containing sequences randomized in non crucial positions of the original peptide. Mini libraries were screened for solubility and inhibitory activity. This procedure enabled us to obtain a new peptide with a better solubility and identical inhibitory activity
Branched multimeric peptides for tumor diagnosis and therapy
No full textThe instant invention refers to in vivo stable branched peptides, in particular derived from the sequence of Neurotensin (NT) and Luteinizing hormone-releasing hormone (LHRH), conjugated to functional units for specific targeting of cancer cells, either for tumor diagnosis or therapy
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