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    Home > Biochemistry News > Biotechnology News > Common questions and answers for peptide synthesis.

    Common questions and answers for peptide synthesis.

    • Last Update: 2020-10-29
    • Source: Internet
    • Author: User
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    1. How do I save
    synthetic polypeptide
    ?polypeptides are stable at -20 degrees C, especially frozen
    dring
    and stored in a dryer, where they can be stored at room temperature before exposing them to air. This will reduce the effects of humidity, and when it is not possible to freeze and dry, the best way is to store it in a small amount of work sample.
    For peptides containing Cys, Met orTrP, deoxygenation buffers are essential for their dissolution, as they are prone to air oxidation, and the slow flow of excess peptide nitrogen or argon before sealing the bottle also reduces oxidation. Peptides containing Gn or Asn are also prone to degradation, and all of these peptides have a limited lifespeed compared to those that do not contain these problematic desosides.
    2. What is the solubility of peptides? What solvents are soluble?
    solvent for most peptides is ultra-pure pumped water. Acetic acid or ammonia water is important for the dissolution of alkaline or acidic peptides, respectively. These methods of insoluble peptides require DMF (dimethyl methamide), niacin, guanidinium (salt), chloride (chloride), or acetonitrile (acetylene) to dissolve, and these solvents may have side effects in some experiments. Therefore, we recommend that you pay attention to the design of peptides.
    Ala, Cys, Ile, Leu, Met, Phe and Val will all increase the difficulty of dissolving peptides.
    3. How does the preservation of peptides work?1mg or less of polypeptides are packed in net weight, the declared vial weight does not contain the relevant anti-ions and water. For example,
    of peptides
    by the analysis of amino acids is 80%, and in a sample of 1 mg, the gross weight in the bottle is 1.25 mg.
    a large number of peptides to gross re-calculate. The indicated weight contains the relevant anti-ions and water, for example, the percentage of peptides in a 25 mg sample is 90%, then the actual peptide content is 25 mg ×90% x 22.5 mg
    The purity of the peptide may be 100%, while the content of the peptide is determined by the resistance of the charged group (e.g. Arrg, Lys) to the hydrophoreticity of the peptide. This is the characteristics of synthetic peptides themselves.
    all products should be stored in the refrigerator, preferably at -20C. Most peptides can be stored in this way for several years unchanged.
    solution peptide is far more unstable than freeze-dried form, the solution should be neutral pH (pH5-7), -20 degrees C preserved, in order to avoid repeated freezing and thawing of samples, it is best to be divided into small sample storage. A sample frozen after not used up, should be thrown away, bacterial degradation sometimes becomes a solution peptide trouble, in order to overcome this, peptides should be dissolved in sterile water, or peptide solution with 0.2 m membrane
    filtration
    .
    . How do I reconstruct the peptide reconstruction process?
    most peptides are dissolved in sterile steaming water. When dissolving for the first time, care should be paid to making the initial concentration greater than the required concentration, which allows for the addition of other dissolving agents or buffer salts if the peptides are only limited in solubility.
    If peptides have limited solubility in water, there are several options to help dissolve:
    with acetic acid (including Arrg, Lys, His) for alkaline peptides
    lu)
    is also useful for extremely hydrophobic peptides with 10%
    organic
    modifiers (acetonitrile, Methanol)
    extremely insoluble peptides with DM50 or DMF
    guanidine hydrochloride or arachloride, and with the above method, acoustic treatment is also an effective means of dissolving polypeptides.
    .
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