Peptides are commonly used in medicine, materials, dyes and other fields, and the solubility of peptides is also a key factor in the success of laboratory experiments.

Insoluble peptides usually refer to peptide or protein molecules that are difficult to dissolve in aqueous solutions. Purification of these biomacromolecules is challenging due to their limited solubility.

In general, the solubility of a polypeptide is closely related to the amino acid sequence of the entire peptide chain.

Generally, when the overall acidic polypeptide is difficult to dissolve, an appropriate amount of alkaline solution can be added, and when the acidic polypeptide is difficult to dissolve, an appropriate amount of acidic solution can be added.

When the sequence contains a large number of hydrophobic amino acids or neutral amino acids, it is difficult to directly dissolve in water, generally need to add a small amount of organic solvent, dissolved completely with a large amount of distilled water dilution, commonly used organic solvents are acetonitrile, DMSO, DMF, propanol, isopropanol and so on.

It should be noted that when the peptide chain contains Met or Cys, it cannot be dissolved by DMSO, which is likely to lead to the oxidation of the S contained in the peptide chain. In addition, in order to help customers design peptides to achieve good experimental results, we generally give customers some effective suggestions on the physical properties, chemical properties and molecular structure of peptide chains. (below pictrue)

It is widely used in the industry

(1) Drug research and development: purification technology of insoluble peptides is of great significance in drug research and development. Many biologic drugs and drug candidate compounds belong to insoluble peptides, and the improvement of purification technology will help to promote the development of new drugs more quickly and efficiently.

(2) Biomedical research: In biomedical research, purification of insoluble peptides is widely used to study the structure and function of specific proteins. This is of great value for deeper understanding of biological processes and for the discovery of new therapeutic targets.

(3) Industrial production: In the industrial production of biomedical engineering, the improvement of insoluble peptide purification technology can reduce production costs and improve product quality, so as to better meet market demand.

The technical key to the purification technology of insoluble peptides is how to increase the solubility of insoluble peptides, and there are three commonly used methods:

(1) Modification of the C-terminal and N-terminal of the peptide chain: for acidic peptides, we recommend C-terminal acetylation modification, and for basic peptides, we recommend n-terminal amination modification.

(2) Modify the amino acid sequence in the peptide chain: Some sequences contain a large number of continuous hydrophobic amino acids, such as W, F, V, I, L, M, Y. When these hydrophobic amino acids are repeated in large numbers or continuously in the sequence, the whole peptide chain is generally insoluble. In order to increase the polarity and hydrophilicity of the peptide, we will also advise customers to extend the sequence without affecting the experimental results. Or increase solubility by reducing the number of hydrophobic amino acids.

(3) Change the residues of hydrophobic amino acids in the sequence: Replacing the hydrophobic amino acids in the sequence with soluble amino acids can achieve the effect of increasing solubility. We usually replace hydrophobic amino acids with Gly and Ala, which usually achieve a better dissolution effect, which is also a conservative but effective way to enhance the solubility of polypeptides.

Motif has a senior technical team, professional equipment, skilled synthesis and purification process and rich experience in the case, so that we fully have the ability to solve a variety of difficult peptides problems and capabilities.

Shortening the experimental period of customers, improving the experimental efficiency of customers, and assisting customers to achieve better results in scientific research projects have always been the purpose and goal of our company's services.

At present, MOTIF has been successfully synthesized as follows: Fmoc-Ser-Ser-Ser-Ser-Ser-OH (Figure below)