Borchman D, Delamere N A, Paterson C A
Department of Ophthalmology, University of Louisville School of Medicine, Kentucky Lions Eye Research Institute 40202.
Invest Ophthalmol Vis Sci. 1988 Jun;29(6):982-7.
Membrane-rich vesicle preparations of rabbit and bovine lenses were prepared in such a manner as to preserve ATPase activity. The lipid:protein ratio of these preparations was increased 22- to 33-fold with a 94% recovery of total phospholipid. Using this preparation, calcium stimulated ATPase was routinely determined in both individual lenses and in pooled specimens. The pattern of stimulation of ATPase activity by a range of calcium concentrations was found to be similar in membrane preparations of epithelium and cortex, from rabbit and bovine lenses. The concentration of calcium necessary for half-maximal stimulation of ATPase activity was approximately 10(-6) M. Calcium concentrations in excess of 10(-4) M reduced the ATPase activity. Calcium-ATPase was undetectable in the lens nuclear region of both species. The regional distribution of sodium-potassium ATPase was also measured.
以保留ATP酶活性的方式制备了兔和牛晶状体富含膜的囊泡制剂。这些制剂的脂质与蛋白质之比增加了22至33倍，总磷脂回收率为94%。使用该制剂，常规测定了单个晶状体和混合标本中的钙刺激ATP酶。发现一系列钙浓度对ATP酶活性的刺激模式在兔和牛晶状体的上皮和皮质膜制剂中相似。ATP酶活性半最大刺激所需的钙浓度约为10^(-6) M。超过10^(-4) M的钙浓度会降低ATP酶活性。在这两个物种的晶状体核区域均未检测到钙ATP酶。还测量了钠钾ATP酶的区域分布。
