Objective: To analyze the
constituent proteins in donkey hide,the key ingredient for Ejiao,an important traditional Chinese
medicine for the blood-related conditions,in hope to eventually decipher the biochemical mechanism behind Ejiao's prominent medicinal efficacy.Method: Two methods were employed to extract
proteins in donkey skin.One used TriPure isolation reagent to extract the total proteins in donkey skin. Another used 1% sodium dodecyl sulfate(SDS) to heat the sample at 100 ℃ overnight.And then sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE) and capillary HPLC were used to analyze the component of proteins.Result: There are not only collagen α_1(Ⅰ) and collagen α_2(Ⅰ),but also serum albumin in donkey skin.The content is over 25% in total proteins with the method of TriPure isolation reagent.The content of donkey serum albumin is up to 20% with the method of 1% SDS heating.And two bands,molecular weight are nearly 200 kDa,were found on 7.5% SDS-PAGE.Extracted these proteins to analyze with capillary HPLC,they were found to be the complex products of collagen and serum albumin of donkey.Conclusion: Donkey serum albumin is a main protein component in the hide,which is a clue to expose the effect of Ejiao on blood.