Further characterization of mammalian ceramide kinase: substrate delivery and (stereo)specificity, tissue distribution, and subcellular localization studies
作者:Helena Van Overloop、Sofie Gijsbers,、Paul P. Van Veldhoven
DOI:10.1194/jlr.m500321-jlr200
日期:2006.2
(HsCERK) was analyzed with regard to dependence on divalent cations and to substrate delivery, spectrum, specificity, and stereoselectivity. Depending on the chain length of the ceramide, either albumin for short-chain ceramide or a mixed micellar form (octylglucoside/cardiolipin) for long-chain ceramide was preferred for the substrate delivery, the former resulting in higher activities. Bacterially expressed
分析了重组人神经酰胺激酶(HsCERK)的二价阳离子依赖性以及底物递送,光谱,特异性和立体选择性。根据神经酰胺的链长,短链神经酰胺的白蛋白或长链神经酰胺的混合胶束形式(辛基葡萄糖苷/心磷脂)可用于底物递送,前者可产生更高的活性。细菌表达的HsCERK高度依赖于Mg2 +离子,而很少依赖于Ca2 +离子。看到对d-赤型异构体的明显偏好。各种N-酰化的氨基醇都没有底物,但N-己基-1-O-十六烷基-2-脱氧-2-氨基-sn-甘油和N-十四烷酰基-2S-氨基-1-丁醇被磷酸化,表明识别不需要仲羟基。HsCERK的属性,在CHO细胞中表达的蛋白与细菌表达的蛋白相似,包括Mg2 +依赖性。在小鼠中,在睾丸和小脑中发现最高的活性,并且在亚细胞分级分离时,活性主要在微粒体级分中恢复。这与CHO细胞中的质膜定位相吻合,这是由N端假定的pleckstrin域介导的。没有发现最近描述的多重脂质激酶使神经酰胺磷