n-Alkanols가 소의 대뇌피질 Synaptosomal Plasma Membrane Vesicles로부터 추출 제제한 총지질 인공세포막 이중층간에 형성된 비대칭적 유동성에 미치는 비대칭적 영향

Transbilayer Effects of n-Alkanols on the Fluidity of Model Membranes of Total Lipids Extracted from Synaptosomal Plasma Membrane Vesicles

한국산 2년생 소의 대뇌피질로부터 synaptosomal plasma membrane vesicles(SPMV)를 분리한 후 이 SPMV로부터 추출한 총지질로서 인공세포막(SPMVTL)을 제제하였다. SPMVTL의 outer monolayer에 trinitrophenyl group을 공유결합시킴으로써 SPMVTL이중층에 분포된 형광 probe 1,6-diphenyl-1,3,5-hexatriene(DPH)중 outer monolayer에 분포된 DPH형광만을 소광케 하였다. 형광분석기를 통하여 SPMVTL의 inner monolayer에 비하여 outer monolayer의 유동성이 크다는 것을 확인하였다. n-Alkanols는 SPMVTL지질 이중층(inner+outer monolayers)의 회전확산운동을 증가시키되 탄소수 두개가 증가될 때마다 그 효력이 약10배 가량 증가된다는 것을 알았다. 그러나 1-decanol의 경우에는 1-nonanol에 비하여 그 효력이 낮아지는 소위 cut-off현상이 나타났다. 뿐만 아니라 n-alkanols는 SPMVTL의 inner monolayer에 비하여 outer monolayer의 회전확산운동을 주로 증가시켰다. 하지만 n-alkanols의 탄소수가 증가됨에 따라 outer monolayer에 대한 선택적인 작용이 감소된다는 것도 확인되었다.

Selective quenching of 1,6-diphenyl-1,3,5-hexatriene (DPH) by trinitrophenyl groups was utilized to examine the transbilayer fluidity asymmetry of model membranes of total lipids (SPMVTL) extracted from synaptosomal plasma membrane vesicles (SPMV). The polarization (P), anisotropy (r), limiting anisotropy $(r_{\infty})$, and order parameter (S) of DPH in the inner monolayer were 0.031, 0.025, 0.033, and 0.070, respectively, greater than calculated for the outer monolayer of SPMVTL. Selective quenching of DPH by trinitrophenyl groups was also utilized to examine the effects of n-alkanols on the individual monolayer structure of SPMVTL. n-Alkanols fluidized the hydrocarbon region of bulk SPMVTL, and the potencies of n-alkanols up to 1-nonanol increased with carbon chain length. It appears that the potencies in bilayer fluidization increase by 1 order of magnitude as the carbon chain length increases by two carbon atoms. The cut-off phenomenon was reached at 1-decanol, where further increase in hydrocarbon length resulted in a decrease in pharmacological activity. The n-alkanols had greater fluidizing effects on the outer monolayer as compared to the inner monolayer of SPMVTL, even though these selective effects tended to become weaker as carbon chain length increased. Thus, it has been proven that n-alkanols exhibit selective rather than nonselective fluidizing effects within transbilayer domains of SPMVTL.