Noeske-Jungblut C, Krätzschmar J, Haendler B, Alagon A, Possani L, Verhallen P, Donner P, Schleuning W D
Research Laboratories of Schering AG, Berlin, Germany.
J Biol Chem. 1994 Feb 18;269(7):5050-3.
The saliva of Triatoma pallidipennis, a blood-sucking triatomine bug (Hemiptera, family Reduviidae, subfamily Triatominae) was found to contain a factor that specifically inhibits collagen-induced platelet aggregation. The 19-kDa protein was purified to homogeneity and named pallidipin. Collagen-mediated aggregation of platelets in plasma and of washed platelets was inhibited with the same efficacy. No inhibition of aggregation stimulated by other effectors (ADP, thrombin, thromboxane A2 mimetic U46619, phorbol ester) was detected. Pallidipin had no effect on platelet adhesion to collagen but inhibited ATP release from platelets. It interacted reversibly with platelets and may share with collagen a common target on them. The protein exhibits a unique primary structure (predicted from cDNA clones) with no significant similarity to other previously described sequences. The protein produced in recombinant baby hamster kidney cells had antiaggregatory effects similar to those of native pallidipin. Availability of recombinant pallidipin will allow further investigation of the precise mechanism of action.
人们发现，吸血锥蝽（半翅目，猎蝽科，锥蝽亚科）苍白真锥蝽的唾液中含有一种能特异性抑制胶原蛋白诱导的血小板聚集的因子。这种19 kDa的蛋白质被纯化至同质，并命名为苍白蛋白。胶原蛋白介导的血浆中血小板和洗涤后血小板的聚集受到同等程度的抑制。未检测到对其他效应物（ADP、凝血酶、血栓素A2模拟物U46619、佛波酯）刺激的聚集有抑制作用。苍白蛋白对血小板与胶原蛋白的黏附没有影响，但抑制血小板释放ATP。它与血小板可逆性相互作用，可能与胶原蛋白在血小板上有共同靶点。该蛋白质具有独特的一级结构（由cDNA克隆预测），与其他先前描述的序列无明显相似性。在重组幼仓鼠肾细胞中产生的该蛋白质具有与天然苍白蛋白相似的抗聚集作用。重组苍白蛋白的可得性将有助于进一步研究其精确作用机制。
