Domains of surfactant protein A that affect protein oligomerization, lipid structure and surface tension
Domains of surfactant protein A that affect protein oligomerization, lipid structure and surface tension
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DOI：
10.1016/s1095-6433(01)00309-9
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发表时间：
2001-05-01
影响因子：
2.3
通讯作者：
McCormack, FX
中科院分区：
文献类型：
--
作者：
Palaniyar, N;Ikegami, M;McCormack, FX
表面活性蛋白A（SurfactantProteinA，SP-A）是肺表面活性物质中含量丰富的一种蛋白质，具有多种功能。在这篇综述中，我们专注于SP-A的每个结构域的蛋白质寡聚化的功能，脂质的结构组织和表面活性剂的表面活性性质的结构重要性，重点是超微结构分析。SP-A的N-末端结构域是二硫键依赖性蛋白寡聚化以及磷脂结合和聚集所必需的，但没有证据表明该结构域直接与脂质膜相互作用。胶原样结构域对于SP-A的稳定性和寡聚化是重要的。它也有助于形状和尺寸的分子，并似乎决定膜间距的脂质聚集体，如共同的髓鞘和管状髓鞘。SP-A的颈部结构域主要参与蛋白质三聚化，这对许多蛋白质功能至关重要，但它似乎不直接参与脂质相互作用。SP-A的球状C-末端结构域在脂质结合和更复杂的功能如弯曲膜的形成和/或稳定中起着重要作用。在最近的工作中，我们已经确定，在血清蛋白抑制剂的存在下，表面活性剂的低表面张力的维持需要分子的C-末端和N-末端结构域之间的合作相互作用。SP-A的这种作用需要蛋白质的高度寡聚组装，并且可以通过蛋白质的活性介导以改变表面活性剂脂质聚集体的形式或物理状态。(C)2001 Elsevier Science Inc. All rights reserved.
Surfactant protein A (SP-A) is an abundant protein found in pulmonary surfactant which has been reported to have multiple functions. In this review, we focus on the structural importance of each domain of SP-A in the functions of protein oligomerization, the structural organization of lipids and the surface-active properties of surfactant, with an emphasis on ultrastructural analyses. The N-terminal domain of SP-A is required for disulfide-dependent protein oligomerization, and for binding and aggregation of phospholipids, but there is no evidence that this domain directly interacts with lipid membranes. The collagen-like domain is important for the stability and oligomerization of SP-A. It also contributes shape and dimension to the molecule, and appears to determine membrane spacing in lipid aggregates such as common myelin and tubular myelin. The neck domain of SP-A is primarily involved in protein trimerization, which is critical for many protein functions, but it does not appear to be directly involved in lipid interactions. The globular C-terminal domain of SP-A clearly plays a central role in lipid binding, and in more complex functions such as the formation and/or stabilization of curved membranes. In recent work, we have determined that the maintenance of low surface tension of surfactant in the presence of serum protein inhibitors requires cooperative interactions between the C-terminal and N-terminal domains of the molecule. This effect of SP-A requires a high degree of oligomeric assembly of the protein, and may be mediated by the activity of the protein to alter the form or physical state of surfactant lipid aggregates. (C) 2001 Elsevier Science Inc. All rights reserved.