Interfacial Regulation of Acid Ceramidase Activity
Interfacial Regulation of Acid Ceramidase Activity
复制标题
酸性神经酰胺酶活性的界面调节
DOI：
--
复制
发表时间：
2001
影响因子：
4.8
通讯作者：
K. Sandhoff
中科院分区：
文献类型：
--
作者：
T. Linke;G. Wilkening;F. Sadeghlar;Heidi Mozcall;K. Bernardo;E. Schuchman;K. Sandhoff
神经酰胺的溶酶体降解由酸性神经酰胺酶催化，并且需要鞘脂激活蛋白（SAP）作为体内辅因子。本研究的目的是探讨如何水解神经酰胺的酸性神经酰胺酶在水膜界面鞘脂激活蛋白的存在下，在脂质体测定系统。当将双（单酰基甘油）磷酸盐、磷脂酰肌醇和磷酸多萜醇等阴离子溶酶体磷脂掺入含有底物的脂质体中时，在不存在和存在SAP-D的情况下，膜结合神经酰胺的降解均显着增加。在膜曲率增加的囊泡中观察到更高的神经酰胺降解速率。稀释试验表明，酸性神经酰胺酶在催化过程中仍然结合到脂质体表面。不仅SAP-D，而且SAP-C和SAP-A，被发现是神经酰胺水解的刺激剂在阴离子磷脂的存在下。这一发现得到了细胞培养研究的证实，其中SAP-A、SAP-C和SAP-D减少了在患有鞘脂激活蛋白原缺乏症的患者的成纤维细胞中观察到的神经酰胺储存量。在表面等离子体共振实验中观察到SAP-D和酸性神经酰胺酶的强蛋白质-脂质相互作用。SAP-D和酸性神经酰胺酶的脂质双层的最大结合发生在pH 4.0。我们的研究结果表明，阴离子，溶酶体脂质所需的有效水解神经酰胺的酸性神经酰胺酶。
The lysosomal degradation of ceramide is catalyzed by acid ceramidase and requires sphingolipid activator proteins (SAP) as cofactors in vivo. The aim of this study was to investigate how ceramide is hydrolyzed by acid ceramidase at the water-membrane interface in the presence of sphingolipid activator proteins in a liposomal assay system. The degradation of membrane-bound ceramide was significantly increased both in the absence and presence of SAP-D when anionic lysosomal phospholipids such as bis(monoacylglycero)phosphate, phosphatidylinositol, and dolichol phosphate were incorporated into substrate-bearing liposomes. Higher ceramide degradation rates were observed in vesicles with increased membrane curvature. Dilution assays indicated that acid ceramidase remained bound to the liposomal surface during catalysis. Not only SAP-D, but also SAP-C and SAP-A, were found to be stimulators of ceramide hydrolysis in the presence of anionic phospholipids. This finding was confirmed by cell culture studies, in which SAP-A, -C, and -D reduced the amount of ceramide storage observed in fibroblasts of a patient suffering from prosaposin deficiency. Strong protein-lipid interactions were observed for both SAP-D and acid ceramidase in surface plasmon resonance experiments. Maximum binding of SAP-D and acid ceramidase to lipid bilayers occurred at pH 4.0. Our results demonstrate that anionic, lysosomal lipids are required for efficient hydrolysis of ceramide by acid ceramidase.
人 GM2 激活蛋白的表达和特异性。
DOI：
--
发表时间：
1994
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Wu,YY;Lockyer,JM;Sugiyama,E;Pavlova,NV;Li,YT;Li,SC
通讯作者：
Li,SC
DOI：
10.1016/0005-2736(91)90295-j
发表时间：
1991-01-30
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
MACDONALD, RC;MACDONALD, RI;HU, LR
通讯作者：
HU, LR
神经酰胺作为 1 α,25-二羟基维生素 D3 诱导的 HL-60 细胞分化的脂质介质的作用。
DOI：
--
发表时间：
1990
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Okazaki,T;Bielawska,A;Bell,RM;Hannun,YA
通讯作者：
Hannun,YA