Takagi T, Maezawa S, Hayashi Y
J Biochem. 1987 Mar;101(3):805-11. doi: 10.1093/jb/101.3.805.
Subunit molecular weights of the (Na+,K+)-ATPase of canine renal outer medulla were estimated in the presence of sodium dodecyl sulfate (SDS) by the measuring system consisted of components connected in the following sequence: a TSK-gel G3000 SW column, a UV spectrophotometer, a low-angle laser light scattering photometer, and a differential refractometer. Polypeptide molecular weights of the alpha- and beta-subunits were determined to be 117,900 and 39,400, respectively. The measurement required the extinction coefficient at 280 nm of the sample polypeptide in addition to the outputs from the three detectors. The extinction coefficients at 280 nm of the alpha- and beta-subunits were determined to be 0.931 and 1.41 ml X mg-1 X cm-1, respectively by the quantitative amino acid analysis. The above procedure seems to be most appropriate to determine uniquely the composition of subunits molecular weights of an oligomeric membrane protein.
采用由按以下顺序连接的组件组成的测量系统，在十二烷基硫酸钠（SDS）存在的情况下，估算犬肾外髓质（Na +，K +）-ATP酶的亚基分子量：TSK-gel G3000 SW柱、紫外分光光度计、低角度激光光散射光度计和示差折射仪。α和β亚基的多肽分子量分别确定为117,900和39,400。除了三个检测器的输出外，该测量还需要样品多肽在280nm处的消光系数。通过定量氨基酸分析，α和β亚基在280nm处的消光系数分别确定为0.931和1.41ml·mg-1·cm-1。上述程序似乎是唯一确定寡聚膜蛋白亚基分子量组成的最合适方法。
