1994 Fiscal Year Final Research Report Summary
Resolution of saccharide structure and biochemical and immunological characterization of unknown glycoprotein which reacts with the antibody of milk fat globule membrane protein
Project/Area Number |
05660129
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
食品科学・栄養科学
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Research Institution | Utsunomiya University |
Principal Investigator |
KANNO Choemon Utsunomiya University Applied Biochemistry Professor, 農学部, 教授 (30011969)
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Project Period (FY) |
1993 – 1994
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Keywords | Bovine milk / Milk fat globule membrane / Glycoprotein / Monoclonal antibody / GP-88 glycoprotein / Lectin affinity / Saccharide chain structure / Antibody affinity chromatography |
Research Abstract |
1. Monoclonal antibody to PAS-4 glycoprotein which is a major constituent protein of bovine milk fat globule membrane was prepared and designated KAS-4. In addition, some proteins which react with KAS-4 was found in milk whey protein and also named as GP-88. GP-88 was glycoprotein and molecular weight was estimated to 88,000 on SDS-PAGE. 2. GP-88 was purified from whey protein by affinity chromatography on Protein G and then KAS-4.Purified GP-88 was a single band on SDS-PAGE.Molecular weight of GP-88 treated with N-glycanase was estimated to 57,000. Biochemical properties of GP-88 and PAS-4 were compared. 3. In addition, epitope of KAS-4 to GP-88 and PAS-4 was examined by immunoblotting after treatment with trifluoromethanesulfonic acid and N-glycanase. Epitope was found in protein moiety.Furthermore, fragments after digestion with trypsin were analyzed on HPLC of C8 and C18 reversed columus and an active peptide to KAS-4 from both GP-88 and PAS-4 was detected by ELISA. 4. The contents of GP-88 in whey and PAS-4 in milk fat globlule membrane in laction periods were determined. It was found that GP-88 content increased the proceeding of laction, whereas PAS-4 content decreased. 5. N-Linked saccharide chains were removed from GP-88 by hydrazine hydrolysis, and the structure of sugar chains was analyzed by size estimation on HPLC,sequential hydrolysis with exoglycosidases, acetolysis, and methylation analysis on GC-MS.A representative structure was proposed as shown in the following.
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