A Study On Sugar Chain Structure And Healthy Function Of Glycoprotein Isolated From Sweet Potato (Ipomoea Batatas LAM)

Having exploited Beijing No.2 sweet potato as material in this dissertation and utilizing a series of modern technologies such as isolation and purification technology, medical analysis technology, legal healthy evaluation method, molecular biological technology, instrument analysis technology and chemical modified method of biological large molecular, the author has systematically studied the sugar chain (SPG-1-P) structure of sweet potato glycoprotein (SPG) and its healthy function. Main results achieved in this research as follows:(1) Four grades of sweet potato glycoprotein SPG-1, SPG-2, SPG-3, SPG-4 were isolated and purified from Beijing No.2 sweet potato through modern isolation and purification technology. Their ratios were 1.23, 0.03, 0.14, 0.05% respectively. By means of Sepharose CL-6B, ConA-Sepharose and HPLC, each grade was sole peak. The molecular weight of SPG-1, SPG-2, SPG-3 and SPG-4 was 49.97, 28.36, 10.68, 8.25 + 104 respectively by Sepharose G-100 determination and by HPLC, their molecular weights were 50.83, 29.06, 11.19, 8.60+104 respectively. The four grades of sweet potato glycoprotein were neutral glycoconjugates containing no starch, no reduction sugar and no polyphenol rather than protein. The total sugar content of SPG-1, SPG-2, SPG-3, and SPG-4 was 97.32, 92.54, 76.65, 99.14% respectively and their contents of protein was 2.15, 6.83 , 22.36, 0.43% respectively. All of the four grades were O- glycoprotein.(2) Sugar chain SPG-l-P was obtained from SPG-1 by means of fi-elimination reaction release and modern isolation and purification, which presented single symmetrical peak in Sepharose CL-6B column and capillary electrophoresis,. And the molecular weight of SPG-l-P determined by Sepadex G-100 and by HPLC was 40.67 + 104 and 39.24 + 104 respectively.(3) Employing chemical methods and instrument analysis technology, the author obtained the possible primary structure of SPG-l-P as follows: (-a-D-6Glcp1-)n -.The higher structure of SPG-l-P was mainly composed of fiber sugar (C6H12O6) crystal and contained some non-crystal.The crystal system of SPG-l-P was monoclinic unit cell. Each crystal cell was composed of 8 glucoses and it's crystal cell parameters were a=0.664nm, b=1.2nm, c=1.97nm. Aqueos solution of SPG-l-P had an apparently positive Cotton effect at 20 C.(4) Combining modern medical analysis technology, legal healthy function evaluation with modern molecular biological technology, the author evaluated immunoregulation of SPG. The results were as follows: 1. SPG-1 could enhance immunoregulation within the dosage of intraperitoneal injection of 0 -80mg/kg.d and presented typical dose-effect relationship. The enhancement effect in immunological regulation was realized by numerous channels such as enhancing nonspecific immunity, cellular immunity, body fluid immunity, IL-1a activity and its mRNA expression, PKC activity, the contents of DNA and RNA and the appearance of 1FN,and its mRNA expression etc.. 2. The order of enhancing their immune activities by feeding routes of SPG-1 to mice was: IV>IP>PO; The Order of immunoregulation of 4 grades SPG was: SPG-l>SPG-3>SPG-2>SPG-4. 3.When the content of SPG in the crude SPG was equal to that in any grade of pure SPG, crude SPG made the rising rate of phagocytic index k and phagocytic coefficient a be superior to that in pure SPG, which showed other components themselves strengthening immunoregulation or enhancing immunoregulation of SPG existed in crude SPG . 4.The immunoregulation activity of SPG-1 mainly existed in the part of sugar chain, but keeping its molecular structure intact had some effects on its immunoregulation activity; SPG sulphation had reducing effects on the immunoregulation of SPG-1, whereas, after medium and low acetification of-SPG, the immunoregulation of SPG was enhanced. Conversely after high acetification, the immunoregulation of SPG-1 decreased, that is, after introducing sulfuric and acetic acid base in SPG-1, it...