Guidelines for solubility of peptides

 

多肽产品溶解指南

Peptides shorter than 10-15 amino acids will normally be soluble in water or aqueous buffer, unless they contain a very high proportion of hydrophobic amino acids. In general it is recommended to test the solubility of a small quantity of the delivered peptide in an aqueous buffer, unless the peptide is strongly hydrophobic.

 

除非肽段中含有大量的疏水性氨基酸残基,少于10-15个氨基酸残基的多肽通常可以直接溶于水或水性溶剂。一般而言,如果多肽的疏水性不是很强,建议先称取少量多肽进行水溶性试验。

 

The content of hydrophilic (acidic and basic), neutral and hydrophobic amino acids are written on Page 2 in the Certificate of Analysis for your peptide.

 

多肽产品分析证书的第2页上显示有该多肽含有的亲水性(酸性或碱性)、中性和疏水性氨基酸残基的比率

In general longer peptides containing less than 40% hydrophobic amino acids and more than 25-30% hydrophilic amino acids (acidic and basic) will normally dissolve in aqueous solutions (please see page 2 in the certificate of Analysis for your peptide for the distribution between hydrophilic, neutral and hydrophobic amino acids). It is recommended to dissolve these peptides in pure water or a buffered solution like PBS buffer, TRIS buffer etc. If the peptide contains significantly more acidic than basic amino acids, and the peptide is soluble in aqueous buffer in order, it is recommended to dissolve the peptide in a slightly basic buffer in order to increase the solubility. If the peptide contains significantly more basic than acidic amino acids and the peptide is soluble in aqueous buffer it is recommended to dissolve the peptide in a slightly acidic buffer in order to increase the solubility.

 

疏水基少于40%且亲水基多于20%的长链多肽往往可以用水性溶剂溶解(疏水、中性和亲水基的比率请参照产品分析证书的第2页)。建议将此类多肽用纯水或水性缓冲液(例如:PBS缓冲液、TRIS 缓冲液等)进行溶解。当可溶于水的多肽中含有的酸性基显著多于碱性基时,可采用弱碱性溶剂以提高该多肽的可溶性。反之,当可溶于水的多肽中含有的碱性基显著多于酸性基时,则建议采用弱酸性溶剂以提高其可溶性。

 

Longer peptides containing 40-65% hydrophobic amino acids will typically only be partially soluble in aqueous solutions. It is recommended to dissolve these peptides in a small quantity of organic solvent like DMF, TFA, acetonitrile etc. DMSO can also be used (If the sequence does not contain C, W or M). Peptides with moderate hydrophobicity can eventually be dissolved in ethanol. After a peptide has been dissolved in a minimum volume of organic solvent, an aqueous buffer or water can be added dropwise to the solvent. Stop immediately if the solution starts to show turbidity, and if the turbidity exists after some minutes then add more organic solvent, until the solution is clear again.

含有40-65%的疏水基的长链多肽通常只能部分溶解于水性溶剂。这些多肽可以用少量有机溶剂(如DMFTFA、乙腈等)来溶解。 如果肽段中不含半胱氨酸、色氨酸或蛋氨酸,该多肽还可以用DMSO溶解。呈轻度疏水性的多肽通常可以溶于乙醇中。先用最少量的有机溶剂溶解多肽,然后再逐滴加入水或水性溶液。当溶液开始出现混浊时应立即停止加液。混浊现象如果在数分钟内没有消失,可以再加入有机溶剂直到液体变清为止。

 

 

List of sample translations

Sample 2_Medical_Basics: Pathophysiology

Sample 3_Medical Devices_Atherectomy system

Sample 4_Medical:healthcare_patient report 

Sample 5_Phamarceutical_drug mechanism of action

Sample 6_Psychology_test