THE ELECTROPHORETIC MOBILITY OF RABBIT ERYTHROCYTES AND GHOSTS

Measurements of the electrical mobility of washed rabbit red cells and of ghosts produced by hypotonic solutions, freezing-and-thawing, chloroform, and saponin were made in the Abramson horizontal microelectrophoresis cell. These different forms of lysis, which corresponds to a variety of degrees of injury to the red cell, are unaccompanied by any change in electrical mobility. These observations are discussed from the standpoint of the possible structure of the cell membrane and the action of lysins upon it.     

精胺对脂质体及细胞膜融合的作用

本文通过共振能量转移法与三氯化铽荧光法探讨了精胺及其与Ca~(2 )对脂质体及人红细胞膜融合的诱导作用.结果表明,精胺能诱导PS脂质体的凝聚,但不能诱导其融合.精胺能诱导血影膜的融合.精胺与Ca~(2 )一起使用.对脂质体及血影膜的融合都分别有协同增效作用.     

TRANSLATIONAL MOBILITY OF THE MEMBRANE INTERCALATED PARTICLES OF HUMAN ERYTHROCYTE GHOSTS : pH-Dependent, Reversible Aggregation

This paper demonstrates the translational movement along the plane of the human erythrocyte ghost of the membrane particles exposed by freeze-fracture. The membrane particles can be aggregated by incubation of the ghosts in media with a pH in the vicinity of 5 5 or 3 5. The particles are disaggregated in neutral and alkaline media (pH 9 5) and also at pH 4.5 Aggregation of the particles at pH 5.5 is reversible, prevented by prefixation in glutaraldehyde and by media of high ionic strength. Particle aggregation occurs within 2–4 min. These results are consistent with the concept that the erythrocyte ghost membrane is a planar fluid domain formed by a bilayer membrane continuum which is interrupted by localized, yet mobile, proteic intercalations.     

完整人红细胞“发芽”释放无骨骼蛋白囊泡的观察

用Ca~2 -EDTA滴定法、加热法和室温静置法都能使人红细胞发芽并释放出囊泡,但发芽进程各不相同,囊泡大小也有差异。用微分干涉差显微镜和扫描电镜观察发现,发芽有时经芽胚红细胞这一中间阶段,但它决不是大多??数有关文献所提的棘细胞。又发现刚释放出来的囊泡具有“果蒂”样母体膜残留物。还发现发芽过程中常伴有细胞融合现象。据此认为芽胚红细胞极不稳定,它或者通过释放囊泡,或者通过细胞融合来达到稳定态。分析再次证明,发芽释放的囊泡缺失骨骼网络的主要成分,即收缩蛋白和肌动蛋白。     

血影膜及脂质体的融合及其与膜流动性的关系

本文采用Tb/DPA荧光方法研究了血影膜及磷脂酰丝氨酸脂质体在不同Ca~(2 )浓度诱导下的融合动力学过程,并通过改变温度研究了血影膜、PS脂质体的融合与膜流动性的关系.血影膜、PS脂质体的最大融合程度在一定范围内随膜流动性增加而增大,超出此范围则随膜流动增加而减小.对此结果进行了讨论.     

核糖核酸酶抑制因子的制备及其在红细胞中的检测

应用Sepharose-RNase亲和层折柱从人胎盘中分防核糖核酸酶抑制因子(RI),纯化约1000倍,得率为43％。纯RI与Freund佐剂1:1稀释,免疫家免,获得抗血清,效价为1:8。经琼脂糖双扩散法和免疫分析,证明红血球中有特异性RI。存在于红细胞胞浆中,红细胞膜上不存在RI。     

pCMBS对完整红细胞膜阴离子通透性的影响

根据等渗ＮＨ４Ｃｌ溶血动力学,探讨了ｐＣＭＢＳ（对氯汞苯磺酸）对完整红细胞膜阴离子通透性的影响．０．０５ｍｍｏｌ／ＬｐＣＭＢＳ使阴离子通透系数Ｐｃｌ下降为对照的８６．５％;１．０ｍｍｏｌ／Ｌ以上浓度时Ｐｃｌ值反而变大。ｐＣＭＢＳ浓度高于０．３ｍｍｏｌ／Ｌ时,细胞悬浮液在１０ｓ之前光密度下降过快,偏离理论拟合方程且不受ＤＩＤＳ抑制．半胱氨酸对ｐＣＭＢＳ引起的效应有恢复作用。结果表明ｐＣＭＢＳ和股骨架蛋白上特殊－ＳＨ基相互作用,导致ｂａｎｄ３构象改变,致使改变膜时阴离子的通透性。     

钆和镱对人红细胞膜脂及膜蛋白的作用

利用荧光偏振,自旋标标顺磁共振波谱和激光拉曼技术研究了钆和镱对人红细胞膜结构和功能的影响。结果表明,低浓度的Ｇｄ３＋（０．５μｍｏｌ／Ｌ）对（Ｎａ＋＋Ｋ＋）－ＡＴＰ酶和Ｍｇ２＋－ＡＴＰ酶有轻微的激活作用,而随着其浓度的增大,则明显抑制酶的活性,Ｇｄ３＋与Ｙｂ３＋和人红细胞膜作用后,降低膜脂流动性,并使膜蛋白酰胺Ｉ＇－α螺旋振动强度减弱．     

ELECTROPORATION AND FUSION OF HUMAN CANCER CELLS MODIFIED BY AMINO ACIDS AND POLYPEPTIDES

The influence of adsorbed polypeptides on electrofusion of histiocytic U937 and myeloidic K562 cells was extended by the corresponding monomeric amino acids in 0.3 M mannitol solution at pH 6.6 and other pH values. In all cases the monomers showed a similar behavior to the polymers, namely, an increase in the relative fusion yield F_r, or, in the case of sulfur-containing compounds, a decrease in F_r at higher concentrations. These electrostatic effects—dominated by the isoelectric points pI and the pH of the medium—are modified by mechanical interventions (e.g., bridging), because the F_r value also depends on the molecular mass (M_m) of the polypeptides. In fact, it rises with increasing M_m. These results demonstrate the fundamental interactions among cell membranes and proteins, polypeptides, and amino acids, which are responsible for essential life processes.     

没食子酸丙酯和没食子酸异丁酯对人红细胞膜结构与功能的影响

本文应用荧光探剂ANS(1—苯胺—8萘磺酸)、NPN(N—苯基—1—萘胺)和DPH(1.6—二苯基—1.3.5—已三烯)观察没食子酸丙醋和没食子酸异丁酯对人红细胞膜流动性和相变温度以及Na~ -K~ ATP酶活性的影响.实验结果指出该两种化合物均能:(1)降低与膜结合的荧光探剂强度但不改变探剂在水相与膜相的分配比例:(2)降低膜脂的相变温度,增加膜的流动性;(3)抑制红细胞膜Na~ -K~ ATP酶活性;(4)标记红细胞膜的DPH偏振度随化合物浓度的增加而降低,膜的流动性增加.在给定的浓度范围内,两种化合物的效应表现为明显的量效关系与构效关系.从上述结果推测该两种化合物可能是通过改变膜脂结构、膜蛋白的脂类环境而调节膜的功能,成为其治疗疾病的机理之一.     

山莨菪碱对人红细胞膜蛋白及膜脂运动的影响

本文采用自旋标记顺磁共振波谱技术,研究了山茛菪碱对人红细胞膜蛋白和膜脂运动的影响.结果表明:用马来酰亚胺标记的人红细胞膜,加入山茛菪碱后,其顺磁共振波谱中强、弱固定化作用谱的峰值比增大,膜蛋白的运动受到限制.山茛菪碱对红细胞膜脂的作用部位主要在极性头部,并影响膜脂的流动性.本文还对山茛菪碱与红细胞膜作用的可能机制进行了讨论.     

膜融合剂对脂质体及血影膜膜流动性的影响

本文用荧光探针ANS,DPH与A研究了几种膜融合剂对脂质体与血影膜流动性的影响.蔗糖使PS脂质体的脂双层流动性降低,探针越是在极性区流动性越小,说明蔗糖主要作用于脂双层的极性区;蔗糖也使血影膜流动性降低,此作用是可逆的.油酸甘油脂(GMO)使PS脂质体的流动性增加,且越是在疏水区内部,流动性增加得越大,说明GMO主要是作用于脂双层的非极性区:GMO也使血影膜流动性增加,此作用是不可逆的.二甲亚砜(DMSO)对血影膜的作用,两种不同荧光探针不一样,对DPH的作用出现双相让,低浓度与高浓度的作用结果分别与蔗糖和GMO的作用一致.     

血红蛋白对人红细胞膜流动性的影响

本文报道了pH7.5时血红蛋白和红细胞膜的结合效应.在10—45℃温度范围内观察到血红蛋白对膜脂质流动性的限制作用.看来这种限制作用不是脂质过氧化所致,而是血红蛋白和红细胞膜直接作用的结果.对流动性大的膜,血红蛋白的效应也随之增大.高铁血红蛋白及红细胞膜去胆固醇皆能修饰血红蛋白和膜的相互作用.     

PHYSICOCHEMICAL EFFECTS OF ALDEHYDES ON THE HUMAN ERYTHROCYTE

The effects of formaldehyde, acetaldehyde, and glutaraldehyde on human red blood cells were investigated. It was found that (a) The surface negative charge of the erythrocytes at pH 7 was increased 10% by glutaraldehyde, but not by the other two aldehydes. (b) The effect of incomplete fixation of the red blood cells was demonstrated by hemoglobin leakage studies The leakage of hemoglobin subsequent to formaldehyde treatment was especially pronounced Acetaldehyde-fixed cells showed some leakage of hemoglobin after an hour of exposure to the fixative, whereas glutaraldehyde-fixed cells showed no hemoglobin leakage. (c) All three aldehydes caused K⁺ leakage during fixation. The concentrations of K⁺ in the fixing solutions all reached the same level, but whereas the leakage with glutaraldehyde was immediate, that with formaldehyde was more gradual and that with acetaldehyde reached a steady state only after 24 hr. (d) The effects of the aldehydes on red cell deformability and swelling revealed that glutaraldehyde hardened the cells within 15 min, formaldehyde within 5 hr, while acetaldehyde required at least 24 hr to produce appreciable fixation. (e) The hematocrit changes accompanying the fixation process depended upon cell volume changes and loss of deformability.     

不同年龄红细胞(人)的增溶胰岛素受体和胰岛素结合以及依赖于胰岛素的磷酸化反应

1.我们研究了人的不同年龄红细胞的胰岛素受体从膜上增溶后和胰岛素相结合的特征。结果表明,随着红细胞年龄的增加,增溶胰岛素受体和胰岛素的最大结合能力下降;ED_(50)降低,同时受体结合位点数减少。青年红细胞的增溶胰岛素受体数比去年的高一倍,但其亲和性不论在结合平衡状态或动力学状态都基本一致。 2.利用γ-~(32)P-ATP的~(32)P参入量研究了胰岛素对不同年龄红细胞增溶蛋白质及外源蛋白质的磷酸化的影响。在胰岛素存在时,磷酸化分别增加2.3—2.9倍,及3.4—4.4倍。胰岛素刺激青年红细胞的增溶蛋白质的磷酸化的敏感性为老年的2.4倍。 3.研究结果表明,单个人的血样可用来研究胰岛素受体的结合及激酶的性质。