pH-dependent fusion of liposomes using titratable polycations.
pH-dependent fusion of liposomes using titratable polycations.
复制标题
使用可滴定聚阳离子进行 pH 依赖性脂质体融合。
DOI：
10.1021/bi00322a001
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发表时间：
1985
期刊：
影响因子：
2.9
通讯作者：
D. Deamer
中科院分区：
文献类型：
--
作者：
P. Uster;D. Deamer
只有当缓冲液pH低于赖氨酸残基的pKa时，聚赖氨酸才会促进脂质体的广泛膜混合。这一观察结果表明，如果将l -组氨酸均聚物取代为融合原，可以在生理pH范围内调节融合。将微量的多组氨酸添加到由大豆磷脂组成的脂质体中，或添加到模拟质膜脂质组成的磷脂-胆固醇混合物中。定量共振能量转移试验确定了与融合相关的脂质相混合的程度。当pH值为7.4时，未检测到融合，但当pH值降至6.5或更低时，融合迅速而充分。随着囊泡-梭原悬浮液的逐渐酸化，膜混合程度增加。影响融合程度的是每个多组氨酸分子的电荷密度，而不是每个囊泡的总阳离子电荷。融合反应的动力学非常快，因为膜混合在1分钟内完成。如果在加入梭原之前对囊泡悬浮液进行酸化，膜混合速度减慢4倍。这一点，以及当pH值为7.4时加入多组氨酸时所注意到的光散射的轻微增加，表明在中性pH下囊泡的预聚集增强了融合动力学。脂质组成、生理范围内pH对膜混合的调节和快速动力学表明，这种脂质体融合模型可能与理解一些生物融合事件有关。
Polylysine promoted extensive membrane mixing of liposomes only if the buffer pH was below the pKa of the lysyl residues. This observation suggested that fusion could be regulated in a physiological pH range if the homopolymer of L-histidine was substituted as fusogen. Microgram quantities of polyhistidine were added to liposomes composed of soybean phospholipids, or to defined phospholipid-cholesterol mixtures which simulate the lipid composition of plasma membranes. A quantitative resonance energy transfer assay determined the extent of lipid phase mixing related to fusion. No fusion was detected at pH 7.4, but when the pH was lowered to 6.5 or below, fusion was rapid and substantial. The extent of membrane mixing increased with progressive acidification of the vesicle-fusogen suspension. The charge density of each polyhistidine molecule, not the total cationic charge per vesicle, influenced the extent of fusion. The kinetics of the fusion reaction were rapid, as membrane mixing was completed within 1 min. If the vesicle suspension was acidified before fusogen addition, the rate of membrane mixing slowed 4-fold. This, as well as a slight increase in light scattering noted whenever polyhistidine was added at pH 7.4, suggests an enhancement of fusion kinetics by preaggregation of vesicles at neutral pH. The lipid composition, regulation of membrane mixing by pH in a physiological range, and rapid kinetics suggest that this model of liposome fusion may be pertinent to understanding some biological fusion events.
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DOI：
10.1016/s0021-9258(17)44551-0
发表时间：
1983-08
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
A. Ciechanover;A. Schwartz;A. Dautry‐Varsat;H. Lodish
通讯作者：
A. Ciechanover;A. Schwartz;A. Dautry‐Varsat;H. Lodish
DOI：
10.1016/s0021-9258(19)69500-1
发表时间：
1981-04
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
K. Hong;N. Düzgüneş;D. Papahadjopoulos
通讯作者：
K. Hong;N. Düzgüneş;D. Papahadjopoulos
影响因子：
2.9
作者：
STRUCK, DK;HOEKSTRA, D;PAGANO, RE
通讯作者：
PAGANO, RE
影响因子：
2.9
作者：
WANG, CY;HUANG, L
通讯作者：
HUANG, L
分离的大鼠脂肪细胞中胰岛素受体再循环的证据。
DOI：
--
发表时间：
1981
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Marshall,S;Green,A;Olefsky,JM
通讯作者：
Olefsky,JM