Otani H, Monnai M, Kawasaki Y, Kawakami H, Tanimoto M
Laboratory of Applied Biochemistry of Animal Products, Faculty of Agriculture, Shinshu University, Minamiminowa-mura, Japan.
J Dairy Res. 1995 May;62(2):349-57. doi: 10.1017/s0022029900031046.
Bovine kappa-caseinoglycopeptides (i.e. residues 106-169, CGP) were prepared from kappa-casein digested with rennin and a commercial whey protein concentrate. CGP from whey protein concentrate was further divided into seven CGP fractions having different carbohydrate compositions using FPLC. Unfractionated CGP inhibited lipopolysaccharide (LPS)- and phytohaemagglutinin (PHA)-induced proliferative responses of mouse spleen cells and rabbit Peyer's patch cells. The unfractionated CGP also inhibited antibody responses to sheep red blood cells in mouse spleen cell cultures. However, seven CGP fractions having zero to five N-acetylneuraminic acid (NANA) residues had different inhibitory effects on both LPS- and PHA-induced proliferative responses of mouse spleen cells. The inhibitory effect on PHA-induced proliferative responses increased with increasing numbers of NANA residues, whereas that on LPS-induced proliferation was highest with the CGP fraction having two NANA residues. Both inhibitory effects decreased significantly after neuraminidase or chymotrypsin digestion. These findings indicate that both the carbohydrate (particularly the NANA residues) and the polypeptide portions are essential for inhibitory effects on LPS- and PHA-induced proliferative responses of mouse spleen cells.
牛κ-酪蛋白糖肽（即106 - 169位残基，CGP）由用凝乳酶和市售乳清蛋白浓缩物消化κ-酪蛋白制备而成。利用快速蛋白质液相色谱法（FPLC）将来自乳清蛋白浓缩物的CGP进一步分为七个具有不同碳水化合物组成的CGP组分。未分级的CGP抑制脂多糖（LPS）和植物血凝素（PHA）诱导的小鼠脾细胞和兔派伊尔结细胞的增殖反应。未分级的CGP还抑制小鼠脾细胞培养物中对绵羊红细胞的抗体反应。然而，具有零至五个N-乙酰神经氨酸（NANA）残基的七个CGP组分对LPS和PHA诱导的小鼠脾细胞增殖反应具有不同的抑制作用。对PHA诱导的增殖反应的抑制作用随着NANA残基数量的增加而增加，而对LPS诱导的增殖反应的抑制作用在具有两个NANA残基的CGP组分中最高。经神经氨酸酶或胰凝乳蛋白酶消化后，两种抑制作用均显著降低。这些发现表明，碳水化合物（特别是NANA残基）和多肽部分对于抑制LPS和PHA诱导的小鼠脾细胞增殖反应都是必不可少的。
