Lubzens E, Ravid T, Khayat M, Daube N, Tietz A
National Institute of Oceanography, Haifa, Israel.
J Exp Zool. 1997 Aug 15;278(6):339-48. doi: 10.1002/(sici)1097-010x(19970815)278:6<339::aid-jez1>3.0.co;2-p.
The high-density lipoproteins (HDLs) found in the male and female hemolymph of Penaeus semisulcatus de Haan were isolated by NaBr (1.22 g/ml) followed by sucrose gradient (5-25%) ultracentrifugation. The male HDL contained one protein, lipoprotein 1 (LP1), composed of one 110-kDa peptide subunit. The female HDL contained two proteins: 1) the LP1 that was immunoidentical to the male LP1 and was similarly composed of one 110-kDa peptide subunit and 2) vitellogenin (Vg), reacting positively with the rabbit antiserum generated against vitellin (Vt) that was isolated from vitellogenic ovaries. Both Vg and Vt consisted mainly of three polypeptide subunits (200, 120, and 80 kDa) as revealed by denatured PAGE and Western blot. The LP1 from males or females did not react with the Vt rabbit antiserum. Similarly, Vg and Vt did not react with the rabbit antiserum prepared against LP1. Phospholipids (PL) constituted 71-76% of the total lipids in the hemolymph and HDLs of both male and female hemolymph. Cholesterol (Ch) amounted to 17-20%, and small amounts (5%) of diacylglycerols (DAG) were also carried by these HDLs. Both the PL and DAG contained highly unsaturated fatty acids (20:5 omega 3 and 22:6 omega 3) that are transported from the food or hepatopancreas to the tissues, including the vitellogenic ovaries in females. In the present study we show for the first time the separate lipid composition of female LP1 and Vg and compare them with the lipids attached to the Vt. Vg had a lower lipid content than LP1 (540 and 1089 mg/g protein, respectively). Differences were also found in the relative abundance of PL, Ch, and DAG classes in the LP1 in comparison with Vg. Furthermore, small amounts (approximately 3.8%) of triacylglycerols (TAG) were found only in the hemolymph of vitellogenic females, and they were associated with the Vg. Although Vg and Vt were composed of similar polypeptides, their lipid composition was different Vt, in contrast to Vg, carried considerable amounts of TAG (approximately 22%) and only trace amounts of DAG. The significance of the TAG in the hemolymph of vitellogenic females is not known, and the functional relationship between Vg and Vt requires future extensive studies. Lipids were not detected in hemocyanin that was purified from clotted hemolymph.
采用溴化钠（1.22 g/ml），随后进行蔗糖梯度（5 - 25%）超速离心，从斑节对虾的雄性和雌性血淋巴中分离出高密度脂蛋白（HDL）。雄性HDL含有一种蛋白质，即脂蛋白1（LP1），由一个110 kDa的肽亚基组成。雌性HDL含有两种蛋白质：1）与雄性LP1免疫相同且同样由一个110 kDa肽亚基组成的LP1，以及2）卵黄蛋白原（Vg），与针对从卵黄发生期卵巢中分离出的卵黄磷蛋白（Vt）产生的兔抗血清呈阳性反应。变性聚丙烯酰胺凝胶电泳（PAGE）和蛋白质免疫印迹法显示，Vg和Vt主要均由三个多肽亚基（200、120和80 kDa）组成。雄性或雌性的LP1均不与Vt兔抗血清发生反应。同样，Vg和Vt也不与针对LP1制备的兔抗血清发生反应。磷脂（PL）占雄性和雌性血淋巴及HDL中总脂质的71 - 76%。胆固醇（Ch）占17 - 20%，这些HDL还携带少量（5%）的二酰基甘油（DAG）。PL和DAG均含有高度不饱和脂肪酸（20:5 ω3和22:6 ω3），它们从食物或肝胰腺转运至组织中，包括雌性的卵黄发生期卵巢。在本研究中，我们首次展示了雌性LP1和Vg各自的脂质组成，并将它们与附着于Vt的脂质进行比较。Vg的脂质含量低于LP1（分别为540和1089 mg/g蛋白质）。与Vg相比，LP1中PL、Ch和DAG类别的相对丰度也存在差异。此外，仅在卵黄发生期雌性的血淋巴中发现少量（约3.8%）的三酰基甘油（TAG），且它们与Vg相关。尽管Vg和Vt由相似的多肽组成，但其脂质组成不同。与Vg相反，Vt携带大量的TAG（约22%），仅含有痕量的DAG。卵黄发生期雌性血淋巴中TAG的意义尚不清楚，Vg和Vt之间的功能关系需要未来进行广泛研究。从凝固的血淋巴中纯化得到的血蓝蛋白中未检测到脂质。
