Yoshida S, Wei Z, Shinmura Y, Fukunaga N
Faculty of Applied Biological Science, Dairy Chemistry Laboratory, Hiroshima University, Higashi-Hiroshima, Japan.
J Dairy Sci. 2000 Oct;83(10):2211-5. doi: 10.3168/jds.S0022-0302(00)75104-6.
Bovine lactoferrin was separated into lactoferrin-a and lactoferrin-b from bovine colostrum. Lactoferrin-a was eluted at 0.38 M NaCl and lactoferrin-b was eluted at 0.43 M NaCl by carboxymethyl cation-exchange chromatography at pH 7.7, 0.05 M phosphate buffer. The molecular weights were estimated at 84,000 for lactoferrin-a and 80,000 for lactoferrin-b. Lactoferrin-a contents were 258.0 mg/L and lactoferrin-b contents were 524.3 mg/L of colostrum for cow 19. From colostrum to normal milk, total lactoferrin was from 17.1 to 129.4 mg/L during the normal lactational period; however, lactoferrin did not separate clearly into lactoferrin-a and lactoferrin-b. The lactoferrin-a measured from six cows was 258.0, 114.0, 112.8, 64.0, 59.7, and 22.4 mg/ L and the lactoferrin-b 524.3, 331.8, 184.7, 170.7, 129.3, and 44.0 mg/L, respectively. The average was 105.2 mg (31.3%) for lactoferrin-a and 230.8 mg (68.7%) for lactoferrin-b.
从牛初乳中分离出了牛乳铁蛋白的乳铁蛋白-a和乳铁蛋白-b。在pH 7.7、0.05 M磷酸盐缓冲液条件下，通过羧甲基阳离子交换色谱法，乳铁蛋白-a在0.38 M氯化钠处洗脱，乳铁蛋白-b在0.43 M氯化钠处洗脱。乳铁蛋白-a的分子量估计为84,000，乳铁蛋白-b的分子量估计为80,000。对于第19号奶牛，初乳中乳铁蛋白-a的含量为258.0 mg/L，乳铁蛋白-b的含量为524.3 mg/L。在正常泌乳期，从初乳到正常牛奶，总乳铁蛋白含量为17.1至129.4 mg/L；然而，乳铁蛋白并未清晰地分离为乳铁蛋白-a和乳铁蛋白-b。从6头奶牛测得的乳铁蛋白-a含量分别为258.0、114.0、112.8、64.0、59.7和22.4 mg/L，乳铁蛋白-b含量分别为524.3、331.8、184.7、170.7、129.3和44.0 mg/L。乳铁蛋白-a的平均含量为105.2 mg（31.3%），乳铁蛋白-b的平均含量为230.8 mg（68.7%）。
