Instrumentation

  • Multiple peptide synthesizers:

    • AAPPTEC 396 omega — This robotic synthesizer is able to prepare in parallel up to 96 different sequences. Scales range for each batch between 10 and 100 mg.

    • Tetras (Advanced Chemtech) — This asynchronous and very flexible multiple peptide instrument is able to prepare in parallel more than 100 different sequences. Scales range for each batch between 50 mg and 500 mg.

  • Manual reactors for solid phase synthesis — This useful device is largely used when syntheses require full time control.

  • Analytical/semi-preparative HPLC (Beckmann-Coulter, system Gold) — This dual instrument can be used both for sample analyses and purification. One to 50 mg of purified compounds can be recovered depending on the used scale.

  • LCQ Fleet ion trap mass spectrometer (ThermoFisher) — This system is coupled to the HPLC above providing us a reliable LC-MS system used for both analytical and preparative purposes. This system can be used in a completely automated and preprogrammed way for the analysis of about 25 samples per day. The possibility to detect, in real time, the mass of the mixture component allows us to deal with and purify the mixture, which would be otherwise too complex to be separated.

Capabilities

  1. Standard solid phase synthesis of peptides/Fmoc strategy:

    Peptide synthesis is routinely performed using the multiple peptide synthesizer by Fmoc strategy.

    An in-house developed, optimized protocol is employed to obtain the best compromise between minimum time and best analytical quality for multiple automatic synthesis.
     
  2. Peptides including unusual monomers/peptide labeled by fluorescent molecules or metal chelator agents

    Peptides including special building blocks (D or unusual aminoacids, various spacers, etc.,) are very frequently prepared.

    In addition, we often provide peptides with a variety of labels, including biotinylation, addition of fluorescent moieties (Fluorescein and Rhodamine based), or Bifunctional metal chelating agents, a list of which is given below here:

    Dota, a widely used chelating agent for most metal (below)
    Image
    Dota


    Cb-Te2A a copper-64 cross-bridged chelating agent (below)
    Image
    Cb-Te2A

    CHX-A” a cyclohexyl derivative of DTPA
    Image
    CHX-A”
  3. Preparation of Multiple Antigen Peptides (MAP), other branched construct (C-terminal labeled compounds) or cyclic peptides

    MAP molecules of several tumor-avid peptides (TF, ErbB-2, PSMA, alpha-MSH etc) are synthesized using specific 'state of art' or in-home optimized technology to obtain all the required geometry, e.g. Etero or homo MAP's, doubled or tetra-branched, C-teminal labeling etc.

    The following depicts a Structure of a C-terminal Biotin labeled, double armed hetero-MAP, bringing two sequences named 'P30-1' and 'Erb-2'
     
    Image
    Structure of a C-terminal Biotin labeled, double armed hetero-MAP
     

    Cyclic peptides are others challenging constructs prepared by use of combinations of optimized protocols, according to the specific needs.

    The example below shows the structure of a DOTA-labeled cyclic peptides (sequence derived from modified alpha-MSH-avid peptide).
     

    Image
    DOTA-labeled cyclic peptides
  4. Synthesis of combinatorial libraries/deconvolution for identification of better binders:

    Combinatorial libraries are synthesized using either 'mix and split' or by addition of mixture of amino acids. Whatever method is used, the possibility to utilize a multiple automatic synthesizer makes these approaches by far more affordable in terms of timework.

    Deconvolution: Different methods can be used which typically consist of an iterative scanning of each position of the libraries in order to identify the amino acid conferring better binding in the given position.

  5. Peptide Nucleic Acid (PNA) synthesis:

    The synthetic strategy for PNA polymer is a slight modification of the standard Fmoc-chemistry, and it requires the use of manual reaction which we used for synthesis of long (14-18) PNA polymers with very specific anti-sense properties.

    In addition, by using alternate methods/instruments, we also synthesized and purified chimera molecules consisting of a PNA moiety covalently bound to a peptidic sequence and labeled either with fluorescent or radio labeled molecules.

    Linear or branched schematic structures of these conjugates are shown below:

    Image
    chimera molecules consisting of a PNA moiety covalently bound to a peptidic sequence and labeled either with fluorescent or radio labeled molecules

 

Contact information

Please contact Dr. Fabio Gallazzi for information on peptide synthesis, consultation on peptide design and pricing.

Dr. Fabio Gallazzi
Research Assistant Professor
Office: 471b Life Sciences Center
Lab: 442 Life Sciences Center
email: gallazzif@missouri.edu
Phone: 573-882-9024 or 573-884-1281