Custom Peptide Synthesis

QCB is a biochemical company that manufactures and markets high quality custom peptides and custom antibodies for biomedical research.  QCB uses a “total team” approach to design, manufacture, purify and quality test all products to insure that the quality and specifications meet our customer’s requirements.  QCB utilizes proprietary synthesis and purification methods to yield peptides and antibodies of the highest quality.  QCB has over 15 years of experience and has produced over 15,000 peptides for laboratories world wide.

With over fifteen years of experience in the industry, QCB provides high quality customized peptides and antibodies to researchers throughout the world. We have recently expanded our catalog offerings to include more high quality peptides at very competitive prices. An additional service that is now being offered is to "customize" catalog peptides to meet individual research needs. Our extensive experience in peptide chemistry allows us to modify amino acids located at either the N or C-terminus of the peptide sequence or located within the sequence. Known cell penetrating peptides can be synthesized to the N or C-terminus or can be added to a MAP complex to increase the delivery of peptide agonist/antagonist to intracellular compartments. MAP complexes can be designed to carry multiple epitopes of the same peptide or multiple peptide sequences of different T-cell epitopes. For example a dual branched MAP complex can be synthesized with a tetanus toxoid fragment at the C-terminus and two naturally processed CD8 T-cell epitopes (VILTNPISM, FSNSTNDILI) to the VEGF KDR receptor on each of the branched arms. Studies have shown that tumor growth is inhibited when mice are vaccinated with both of these anti-angiogenesis peptides (J Immunotherapy, 29: 32-40, 2006). Multi-epitope vaccination also has shown promise with the cytotoxic T cell (CTL) epitopes for tyrosinase and gp100 (J Clin Oncol, 22: 4474-4485, 2004).

Modification of known peptides has been used to elucidate their mechanism of action. When a six histidine tail was added to the N-terminus of the BID BH3 or BIM BH3 peptide, the peptides activated the pro-apoptotic protein BAX. Little activity was observed in the absence of the histidine tail. The increased activity of the histidine tagged peptides was due to the membrane targeting properties of histidine (Molecular Cell, 17: 525-535, 2005, J Biol Chem, 281: 36999-37008, 2006). Similar studies have been carried out with known cell penetrating peptide sequences. Addition of penetratin or an eight arginine tag to the C-terminus of the SMAC/Diablo peptide resulted in the increase binding to the Inhibitor of Apoptosis Protein (IAP) and abrogated the inhibition of IAP on caspase-3, caspase-7 and caspase-9. (Blood, 99: 3419-3426, 2002, J Biol Chem, 277: 44236-44243, 2002, Cancer Res, 63: 831-837, 2003). An eight arginine C-terminus peptide carrier added to the peptide Humanin increased the uptake of Humanin into cells where it bound BID and prevented the translocation of BAX from the cytosol to the mitochondria. The study showed that some of Humanin's anti-apoptotic activity is through the suppression of BID activation of BAX and BAK (J Biol Chem, 280: 15815-15824, 2005).

Our extensive experience in peptide chemistry and HPLC purification of complex peptides, phosphopeptides, long peptide sequences and hydrophobic peptides has been applied to our custom antibody services. We have expanded our antibody services to include Phospho-Specific Site Antibodies(PSSA), Multiple Epitope immunization and customized MAP complexes for Multiple Epitope vaccination and for immunization. Several antibody packages include antigen design, peptide synthesis from 15 to 50 amino acids and peptide conjugation to carrier proteins. Select packages include anti-peptide affinity column purification of serum antibodies.

Let the experienced team at QCB work with you to provide you with the highest quality peptides and functional antibodies to meet your research needs.

Cell Penetrating Peptides as Carriers for Intracellular Protein Delivery

Several short peptide sequences have been identified with cell membrane translocation activity. These peptide sequences can be added to either the N or C terminus of the peptide. Coupling of these cell penetrating peptides to proteins or drugs facilitates their internalization into cells or tissues (J Biol Chem, 276; 5836-5840, 2001, PNAS, 97: 13003-13008, 2000, Cancer Reasearch 63:831-837,2003, Nature Medicine, 10: 305-309, 2004, Cell Mol Life Sci, 62: 1839-1849, 2005).

Polypeptide Affinity Tags to Facilitate the Purification of Target Proteins (Appl Microbiol Biotechnol,60:523-533,2003)

What options are available for custom peptide services?

• Peptide Modifications/BioActive Peptides
• N-terminal acetylation or C-terminal amidation
• Mono or multiple [Serine], [Threonine] or [Tyrosine] phosphopeptides
• Tyrosine sulfate peptides
• Cyclic peptides
• Aldehydes
• Caspase substrates and inhibitors
• Kinase substrates and inhibitors
• Beta Amyloid 1-40, 1-42 and fragments
• Modifications at the N or C terminus
• Biotin
• Fatty acids (Palmitic, Stearic,Myristic)
• Dyes
• Custom Modifications
• Colorimetric/Fluorometric markers AFC, AMC, pNA
• FRET probes Dabcyl/Edans, MCA/DNP
• Multiple Antigenic Peptides (MAP)
• Dual, tetrameric, octameric branches

What is Multiple Antigenic Peptide Technology (MAP)?

Multiple Antigenic Peptide technology (MAP) is a method used to transport peptides into intact cells or to deliver peptide antigens to animals without having to conjugate the peptides to carrier proteins or other complex molecules. The MAP complex is synthesized on an immunogenically inert core matrix of amino acids including lysine residues bearing the branched peptides. This core matrix can be used to generate dual, tetrameric or octameric branches of the peptide. This branching results in a higher ratio of peptide to lysine core which allows more peptide to be delivered to intact cells or animals. The MAP complex also allows for the addition of B or T cell epitopes to either the C or N terminus of the peptide. The MAP core can be synthesized with additional lysine, arginine, or proline rich regions to increase the uptake of the complex into cells. MAP technology is used to negate the difficulties in conjugation of hydrophobic or complex peptides to carrier proteins, to deliver peptide antigens containing internal cysteine residues, to reduce or eliminate the immunogenic response to carrier proteins or used as a drug delivery system to intact cells.

MAP technology also may be used in the targeting of cell surface receptors. Here the MAP core is composed of anionic amino acids to reduce the uptake into cells. The C-terminus of the MAP core contains the site-directed peptide sequence to the cell surface receptor and the branched sequence on the core contains either a T-cell epitope, fluorescent probe or other detecting complexes.

The MAP core can also be customized to contain:

• Tetanus Toxoid Helper Sequence(830-844) at the C-Terminus
• The HIV TAT(48-60) sequence
• Fatty acids (palmitic) attached to basic residues in the core sequence
• A hydrophobic sequence
• A protease sensitive region for the cleavage of the active peptide inside the cell

QCB is now offering Ghrelin & Obestatin as MAP complexes.

Ghrelin and Obestatin have been shown to have a role in the regulation of body weight. Ghrelin has been implicated in stimulating the appetite and increasing food intake while Obestatin has been shown to suppress food intake and decrease body weights in rats. QCB has synthesized both peptides and now will offer to our antibody customers these peptides made as a MAP complex. Our MAP technology has shown to be 85% to 90% successful in generating antibodies to peptide antigens. This success is attributable to the direct synthesis of the peptide to our unique MAP core. MAP technology eliminates the difficult conjugation of hydrophobic or basic peptides to carrier proteins. Also the ratio of peptide to MAP core is higher than peptide conjugated to carrier proteins resulting in more of the peptide being delivered to the host animal. Ghrelin-MAP and Obestatin-MAP are available to be coupled to one of QCB's antibody protocols or be shipped to you ready for immunization in your host animal.

QCB synthesizes all MAP cores in-house. MAP cores can be customized to meet the needs of the researcher. MAP cores synthesized for customers are kept confidential and are not used by QCB for other projects.