쥐간 dolichol의 함유량을 순상 HPLC로 측정한 결과, homogenate가 132 ng/mg protein， rnicrosome에 692 ng/mg protein, cytosol에는 47 ng/mg protein으로서 cytosol 중의 dolichol 총량은 homogenate의 약 13%에 이르는 것을 확인하였다. Cytosol dolichol의 chain distribution의 패턴은 역상 HPLC로 측정한 결과, homogenate의 dolichol과 유사하였다. Cytosol 에 $[^3H]dolichol$을 첨가하고 Sephacryl S-300 column으로 gel filteration을 행하면, 거의 모든 radioactivity가 void volume에 용출되었다. 그러나 유리형의 $[^3H]dolichol$도 일부 같은 fraction에 용출되는 점으로 보아서 종래의 방법으로는 $[^3H]dolichol$의 결합형과 유리형의 분리가 불완전함을 알 수 있었다. 한편, DEAE-Sephacel을 사용한 이온교환 크로마토그래피로는 결합형 $[^3H]dolichol$이 0.3M NaCl 근방에 용출되고 유리형 $[^3H]dolichol$은 전혀 용출되지 않는 점으로 보아 결합형과의 분리가 완전하였다. 또한, 40배 molar excess의 비표식(cold) dolichol을 공존시켰더니 0.3M 근방에 용출되는 $[^3H]dolichol$ peak는 25%로 감소되었다. 이상의 결과로 보아 cytosol에는 음이온교환수지에 흡착되고, dolichol에 대해 포화형의 결합활성을 나타내는 인자가 존재하고 있음을 알 수 있었다.
This paper describes an approach to search cytosolic binding component(s) for dolichol in rat liver. The contents of endogenous dolichol were estimated to be $13.5{mu}g/g$ liver (132 ng/mg protein) in the homogenate, $8.8{mu}g/g$ liver (692 ng/mg protein) in the microsome, and $1.8{mu}g/g$ liver (19 ng/mg protein) in cytosol indicating that about 13% of the hepatic dolichol stayed in the pool of cytosol. With respect to the chain distibution, dolichol-18 and -19 were found predominate in cytosol alike in homogenate. When rat liver cytosol was incubated with $[^3H]dolichol$ and applied to a column of Sephacryl S-300, 40% of total radioactivity appeared at the void volume. On the same chromatography of aqueous dispersion of $[^3H]dolichol$ as a blank, approximately 10% of the radioactivity appeared was eluted at the void volume indicating that the binding assay with gel filtration was not acceptable. When cytosol labeled with $[^3H]dolichol$ was applied to a column of DEAE-Sephacel, a single peak of radioactivity (about 10%) was eluted centered at around 0.3 M NaCl behind a peak of major proteins. On the same ion-exchange chromatography of $[^3H]dolichol$ dispersed in the buffer, no radioactivity was found in a linear gradient of NaCl concentration. When cold dolichol in 400-fold molar excess over $[^3H]dolichol$ was added upon labeling the cytosol, 75% of $[^3H]dolichol$ in 0.3 M NaCl fraction disappered indicating that the binding site(s) are saturable. These results appeared likely that certain acidic and macromolecular component(s) in the cytosol exhibited the specific binding activity with $[^3H]dolichol$.
