Fourier transform infrared studies of secondary structure and orientation of pulmonary surfactant SP-C and its effect on the dynamic surface properties of phospholipids.
Fourier transform infrared studies of secondary structure and orientation of pulmonary surfactant SP-C and its effect on the dynamic surface properties of phospholipids.
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肺表面活性剂 SP-C 二级结构和取向的傅里叶变换红外研究及其对磷脂动态表面性质的影响。
DOI：
10.1021/bi00105a033
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发表时间：
1991
期刊：
影响因子：
2.9
通讯作者：
Mendelsohn,R
中科院分区：
文献类型：
--
作者：
Pastrana,B;Mautone,AJ;Mendelsohn,R
罗格斯大学纽瓦克文理学院化学系，73 Warren Street，纽瓦克，New Jersey 07102，以及新泽西州医学和牙科大学-新泽西医学院麻醉学和生理学系，185 South橙子Avenue，纽瓦克，新泽西07102接收日期：1991年6月4日;修订版《联邦公报》接收日期：1991年8月7日摘要：SP-C是肺表面活性物质的一种高度疏水的3.7kDa蛋白质组分，已从牛肺灌洗液中分离、纯化并重组成1，2-二棕榈酰磷脂酰胆碱（DPPC）和1，2-二棕榈酰磷脂酰甘油（DPPG）的二元脂质混合物。傅里叶变换红外光谱（FT-IR）已被应用于检查SP-C二级结构，平均取向的螺旋段相对于正常的双层膜，和蛋白质的热致性质的磷脂酰基链的影响。此外，在存在和不存在SP-C的情况下，对A/W界面处的磷脂膜进行动态表面测量。发现SP-C（0.5mol%）在脂质囊泡中具有约60%的螺旋二级结构。较高水平（1.5 mol%）的SP-C导致p-1的略微增加。可能是蛋白质聚集的结果。螺旋片段相对于thebilayer法线呈现出约24 °的平均取向角，表明肽的跨双层取向。70%的肽键氢在D20中难以交换的观察结果进一步反映了分子的疏水性质。SP-C产生的二元脂质混合物的热致性的影响不大，从酰基链CH和CD伸缩频率测量。然而，1mol%蛋白质的存在下，显着降低粘度和增加表面膜的弹性，这表明SP-C促进磷脂在水表面上的铺展的机制。肺泡表面活性剂是由II型肺泡细胞分泌的脂质和蛋白质的混合物，其基本物理特性是能够将空气/肺泡界面的表面张力降低到接近于零（Scarpelli，1988）。表面活性剂中的主要脂类是1，2-二棕榈酰磷脂酰胆碱（DPPC），1还含有少量的磷脂酰甘油（PG）、不饱和PC、其它阴离子磷脂和胆固醇。已经鉴定了几种表面活性剂蛋白类。最丰富的是一个家族（称为SP-A），分子量范围为28- 36 K。Ng等人（1983）已经表明这类蛋白质经历可变的翻译后糖基化。人肺SP-A的基因已经被分离和表征（白色等人，1985年）。除了SP-A之外，还存在两种较小的疏水性蛋白质，即SP-B，79个氨基酸的片段，其是来自42-kDa前体的残基201-279的加工产物（Curstedt等人，1988）和SP-C，高度疏水的部分（Johansson等人，1988; Hawgood等人，1987年）。SP-C的N-末端是异质的，主要形式为35个残基长（Jo-hansson等人，1988），猪物种中存在S-棕榈酰化半胱氨酸残基（Curstedt等人，1990年）。最近，Escherson et al.（1990）报道了胶原表面活性剂相关糖蛋白SP-D的分离。各种蛋白质类的功能通常被认为与表面活性剂在A/W界面的吸附和扩散及其再摄取到II型中有关
Department of Chemistry, Newark College of Arts and Sciences, Rutgers University, 73 Warren Street, Newark, New Jersey 07102, and Departments of Anesthesiology and Physiology, University of Medicine and Dentistry of New Jersey—New Jersey Medical School, 185 South Orange Avenue, Newark, New Jersey 07102 Received June 4, 1991; Revised Manuscript Received August 7, 1991 abstract: SP-C, a highly hydrophobic, 3.7-kDa protein constituent of lung surfactant, has been isolated from bovine lung lavage, purified, and reconstituted into binary lipid mixtures of 1, 2-dipalmitoyl-phosphatidylcholine (DPPC) and 1, 2-dipalmitoylphosphatidylglycerol (DPPG). Fourier transform infrared (FT-IR) spectroscopy has been applied to examine SP-C secondary structure, the average orientation of-helical segments relative to the bilayer normal in membrane films, and the effect of protein on the thermotropic properties of the phospholipid acylchains. In addition, dynamic surface measurements were made on phospholipid films at the A/W interface in the presence and absence of SP-C. SP-C (0.5 mol%) was found to possess about 60%-helical secondary structure in lipid vesicles. Higher levels (1.5 mol%) of SP-C resulted in a slight increase of/?-forms, possiblyresulting from protein aggregation. The helical segments exhibited an average angle of orientation of about 24 with respect to thebilayer normal, suggesting a trans-bilayer orientation of the peptide. The observation that 70% of the peptide bond hydrogens are hard to exchange in D20 further reflectsthe hydrophobic nature of the molecule. SP-C produced little effect on the thermotropic properties of the binary lipid mixture, as measured from acyl chain CH and CD stretching frequencies. However, thepresence of 1 mol% protein markedly reduced the viscance and increased the elasticity of surface films, suggesting a mechanism by which SP-C facilitates the spreading of phospholipids on an aqueous surface. The possible physiological consequences of these observations are discussed.I^ lmonary surfactant, a mixture of lipids and proteins se-creted by type II pneumocytes, possesses as its essential physical characteristic the ability to lower surface tension at the air/alveolar interface to near zero (Scarpelli, 1988). The main lipid in surfactant is 1, 2-dipalmitoylphosphatidylcholine (DPPC), 1 with smalleramounts of phosphatidylglycerol (PG), unsaturated PCs, other anionic phospholipids, and cholesterol. Several surfactant protein classes have been identified. The most abundant is a family (termed SP-A) with a molecular weight range of 28-36K. Ng et al.(1983) have shown this class to be subject to variable posttranslational glycosylation. The gene for human pulmonary SP-A has been isolated and characterized (White et al., 1985). In addition to SP-A, two smaller hydrophobic proteins are also present, namely, SP-B, a 79 amino acid fragment that is the processing product of residues 201-279 from a 42-kDa precursor (Curstedt et al., 1988), and SP-C, a highly hydrophobic moiety (Johansson et al., 1988; Hawgood et al., 1987). The N-terminus of SP-C is heterogeneous, the main form being 35 residueslong (Jo-hansson et al., 1988), with S-palmitoylated cysteine residues present in the porcine species (Curstedt et al., 1990). Recently, Persson et al.(1990) have reported the isolation of a col-lagenous surfactant-associated glycoprotein, SP-D. The functions of the various protein classes have generally been assumed to be related to surfactant adsorption and spreading at the A/W interface and its reuptake into type II
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兔表面活性剂相关蛋白的表征。
DOI：
10.1016/0005-2760(83)90164-9
发表时间：
1983
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
Ng,VL;Herndon,VL;Mendelson,CR;Snyder,JM
通讯作者：
Snyder,JM
疏水性低分子量表面活性剂缔合多肽的大小和结构。
影响因子：
2.9
作者：
J. Johansson;T. Curstedt;B. Robertson;H. Jörnvall
通讯作者：
H. Jörnvall
影响因子：
64.8
作者：
R. T. White;D. Damm;Judy Miller;K. Spratt;J. Schilling;S. Hawgood;B. Benson;B. Cordell
通讯作者：
R. T. White;D. Damm;Judy Miller;K. Spratt;J. Schilling;S. Hawgood;B. Benson;B. Cordell
影响因子：
3.4
作者：
K. Rothschild;N. Clark
通讯作者：
N. Clark
兔肺表面活性材料的傅里叶变换红外和差示扫描量热研究。
DOI：
10.1016/0005-2736(87)90349-x
发表时间：
1987
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
Mautone,AJ;Reilly,KE;Mendelsohn,R
通讯作者：
Mendelsohn,R