【项目简介】
Axl (Ufo, Ark), Dtk (Sky, Tyro3, Rse, Brt), and Mer (human and mouse homologues of chicken c-Eyk) constitute a subfamily of the receptor tyrosine kinases. The extracellular domains of these proteins contain two Ig‑like motifs and two fibronectin type III motifs. This characteristic topology is also found in neural cell adhesion molecules and in receptor tyrosine phosphatases. The mouse Axl cDNA encodes an 888 amino acid (aa) precursor that includes an 18 aa signal sequence, a 427 aa extracellular domain, a 21 aa transmembrane segment, and a 422 aa cytoplasmic domain. The extracellular domains of mouse and human Axl share 81% aa sequence identity. These receptors bind the vitamin K-dependent protein growth arrest specific gene 6 (Gas6) which is structurally related to the anticoagulation factor protein S. Binding of Gas6 induces receptor autophosphorylation and downstream signaling pathways that can lead to cell proliferation, migration, or the prevention of apoptosis. This family of tyrosine kinase receptors is involved in hematopoiesis, embryonic development, tumorigenesis, and regulation of testicular functions.
 
【检验原理】
本试剂盒采用双抗体夹心ELISA法。酶标微孔板上预包被有抗小鼠Axl抗体，当加入标准品和待测样本时，标准品和待测样本中的小鼠Axl会和该抗体结合。洗板后，游离的其他成分被洗去，加入辣根过氧化物酶标记的的抗小鼠Axl抗体可与被酶标板捕获的小鼠Axl结合，形成“包被抗小鼠Axl抗体+小鼠Axl+抗小鼠Axl抗体-HRP”免疫复合物。当加入TMB显色底物后，复合物上连接的HRP催化底物反应，生成蓝色产物，终止反应后变为黄色。在450nm处测定OD值，小鼠Axl浓度与OD450值之间呈正比，可通过绘制标准曲线求出标本中小鼠Axl的浓度。