Yamamoto M, Katoh N, Adachi Y, Oikawa S
Fukushima Kenchu Livestock Hygiene Service Center, Japan.
Am J Vet Res. 1998 Jun;59(6):667-72.
To identify, purify, and analyze distribution of apolipoprotein C-III in lipoprotein fractions and to evaluate its concentration in serum from calves, heifers, and cows during various stages of lactation.
Sera from 3 female calves, 3 heifers, and 12 cows during early, middle, late, and nonlactation stages.
Apolipoprotein C-III was identified by use of amino-terminal amino acid sequence analysis of bands separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Purification was performed by extraction with acetone, delipidation with 2-propanol, and 2 chromatographic steps. The apolipoprotein C-III concentration in the total lipoprotein fraction was evaluated by densitometric scanning of the bands for apolipoprotein C-III separated by electrophoresis, using purified apolipoprotein C-III as an internal standard.
Apolipoprotein C-III was identified as 8.2- and 7.3-kd proteins with identical amino acid sequences. The 2 proteins were mainly found in the high-density lipoprotein fraction, then were purified separately. Serum apolipoprotein C-III concentration was significantly (P < 0.05) higher in cows during lactation than in nonlactating cows and was negatively correlated with serum triglyceride concentration (r = -0.620, P < 0.01).
The role of apolipoprotein C-III in cows may involve a function related to lactation.
鉴定、纯化并分析载脂蛋白C-III在脂蛋白组分中的分布，评估其在犊牛、小母牛和奶牛不同泌乳阶段血清中的浓度。
3头雌性犊牛、3头小母牛和12头奶牛在泌乳早期、中期、晚期和非泌乳期的血清。
通过对十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分离的条带进行氨基末端氨基酸序列分析来鉴定载脂蛋白C-III。通过丙酮萃取、异丙醇脱脂和两步色谱法进行纯化。以纯化的载脂蛋白C-III为内标，通过对电泳分离的载脂蛋白C-III条带进行光密度扫描来评估总脂蛋白组分中载脂蛋白C-III的浓度。
载脂蛋白C-III被鉴定为氨基酸序列相同的8.2-kd和7.3-kd蛋白。这两种蛋白主要存在于高密度脂蛋白组分中，随后分别进行纯化。泌乳期奶牛血清载脂蛋白C-III浓度显著高于非泌乳期奶牛（P < 0.05），且与血清甘油三酯浓度呈负相关（r = -0.620，P < 0.01）。
载脂蛋白C-III在奶牛中的作用可能涉及与泌乳相关的功能。
