Watanabe A, Miyamoto T, Katoh N, Takahashi Y
Hokkaido Branch Laboratory, National Institute of Animal Health, Sapporo, Japan.
J Dairy Sci. 1997 Oct;80(10):2372-9. doi: 10.3168/jds.S0022-0302(97)76188-5.
From the normal mammary tissue of a Holstein cow in late lactation, a heat shock protein (90 kDa) was purified by ammonium sulfate fractionation and five-step column chromatography. From 70 g of tissue, 9.5 mg of this heat shock protein were obtained; samples had 98% purity and 19% recovery. The molecular mass of the 90-kDa heat shock protein was estimated to be 86 kDa by SDS-PAGE. Analysis of the amino-terminal amino acid sequence suggested that the protein had been purified as a mixture of two isoforms. The contents of the heat shock protein in cytoplasmic fractions of mammary tissues from Holstein heifers and cows at lactation and involution were measured by quantitative immunoblot analysis using rabbit antiserum raised against the purified heat shock proteins. The contents of the heat shock protein were higher in tissues from lactating cows than in those from heifers and involuting cows. The elevated concentrations of cytoplasmic 90-kDa heat shock protein in lactating tissue suggested that this protein is involved in mammary differentiation and lactation.
从一头处于泌乳后期的荷斯坦奶牛的正常乳腺组织中，通过硫酸铵分级分离和五步柱层析法纯化出一种热休克蛋白（90 kDa）。从70克组织中获得了9.5毫克这种热休克蛋白；样品的纯度为98%，回收率为19%。通过SDS-PAGE估计该90 kDa热休克蛋白的分子量为86 kDa。对氨基末端氨基酸序列的分析表明，该蛋白是作为两种异构体的混合物被纯化出来的。使用针对纯化的热休克蛋白产生的兔抗血清，通过定量免疫印迹分析测量了荷斯坦小母牛以及处于泌乳期和 involution期的奶牛乳腺组织细胞质部分中热休克蛋白的含量。泌乳期奶牛组织中的热休克蛋白含量高于小母牛和 involution期奶牛组织中的含量。泌乳组织中细胞质90 kDa热休克蛋白浓度的升高表明该蛋白参与乳腺分化和泌乳过程。 （注：involution此处可能有误，推测可能是 involutionary stage，即退化期，但按照要求未修改原文错误部分）
