Constitutive expression of a saturable transport system for non-esterified fatty acids in Xenopus laevis oocytes.
Constitutive expression of a saturable transport system for non-esterified fatty acids in Xenopus laevis oocytes.
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非洲爪蟾卵母细胞中非酯化脂肪酸可饱和转运系统的组成型表达。
DOI：
10.1042/bj2970315
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Berk,PD
中科院分区：
文献类型：
--
作者：
Zhou,SL;Stump,D;Isola,L;Berk,PD
在150微米牛血清白蛋白存在下，非洲爪哇卵母细胞摄取[~3H]油酸是游离油酸浓度(Vmax)的可饱和函数。每卵母细胞110+/-4pmoL/h；Km193+/-11 nM未结合油酸)。油酸的摄取比另一种受试物质[35S]溴磺酸盐快三个数量级，并被55 nM未结合棕榈酸酯(Vmax)竞争性抑制。每卵母细胞111+/-14pmol/h；Km424+/-63 nM游离油酸)(P<；0.01)。抗43 kDa大鼠肝脏质膜脂肪酸结合蛋白的抗体也抑制了油酸的摄取，该蛋白是哺乳动物细胞中假定的长链脂肪酸的转运体；中链脂肪酸[14C]辛酸的摄取不受影响。免疫荧光和免疫印迹表明，该抗血清可与卵母细胞表面的单一43 kDa蛋白发生反应。因此，一种与哺乳动物质膜脂肪酸结合蛋白相关的蛋白质可能在非洲爪哇卵母细胞饱和摄取长链脂肪酸方面发挥作用。
In the presence of 150 microM BSA, uptake of [3H]oleate by Xenopus laevis oocytes was a saturable function of the unbound oleate concentration (Vmax. 110 +/- 4 pmol/h per oocyte; Km 193 +/- 11 nM unbound oleate). Oleate uptake was three orders of magnitude faster than that of another test substance, [35S]bromosulphophthalein, and was competitively inhibited by 55 nM unbound palmitate (Vmax. 111 +/- 14 pmol/h per oocyte; Km 424 +/- 63 nM unbound oleate) (P < 0.01). Oleate uptake was also inhibited by antibodies to a 43 kDa rat liver plasma-membrane fatty acid-binding protein, a putative transporter of long-chain fatty acids in mammalian cells; uptake of the medium-chain fatty acid [14C]octanoate was unaffected. Immunofluorescence and immunoblotting demonstrated that the antiserum reacted with a single 43 kDa protein on the oocyte surface. Hence a protein related to the mammalian plasma-membrane fatty acid-binding protein may play a role in saturable uptake of long-chain fatty acids by Xenopus oocytes.