| With the development of biotechnology, the exploitation and application of low molecular weight peptides become more and more extensive, especially for the avalanche of biologically active peptides and antimicrobial peptides, and the discovery of low molecular peptides during cellulose or lignin degradation as well. Now we ordinarily use SDS-PAGE, capillary electrophoresis and high performance liquid chromatography to separation and purification of low molecular peptides. However, SDS-PAGE became the most popular separation methods due to its easy operation and low cost.We tried to do some improvement of the SDS-PAGE and found that it can increase resolution of separating low molecular weight peptides by using high concentrated and cross-linked polyacrylamide or with 6-8M urea. High-molarities or high-pH buffers were also be found to be effective for the separation of peptides. Otherwise, changing the buffer system such as using Tris-Tricine electrode buffer system could also achieve successful resolution of the low molecular weight peptides. But all these improvements were based on the system which used SDS as surfactant. The improved SDS-PAGE systems could seldom separating peptides of molecular weight below 3000.We chose anion surfactant X as denaturant and did some research on the influencing factors of separation effect such as concentration of surfactant X and separating gel, the ionic strength or pH of buffer system, reducing agent, temperature of dealing with samples, the pH of sample buffer and the staining method choice etc. Then we established a new electrophoresis system, named X-Urea-PAGE system. This new system could separate peptides and proteins in the range of l-70KDa.This X-Urea-PAGE system was applied to low molecular weight peptides separations, enzymatic recovery electrophoresis and the second dimension electrophoresis of 2-D gel electrophoresis. Based on this new system, we still... |
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