Sandberg L B, Soskel N T, Wolt T B
J Invest Dermatol. 1982 Jul;79 Suppl 1:128s-132s. doi: 10.1111/1523-1747.ep12546005.
Intense research efforts over the past 18 yr have probed deeply into the structure of the elastic fiber. This began with the elucidation of the demosine crosslinks in elastin and the description of the elastin precursor, tropoelastin, derived from copper-deficient animals. Characterization of the precursor material indicates that it is a single polypeptide chain of approximately 800 amino acid residues containing lysine residues in clusters destined to form the desmosine crosslinks. The molecule contains large areas of hydrophobic sequence interspersed with shorter stretches of polyalanine and the lysines. The shorter structures may be folded into alpha-helices. The larger hydrophobic areas appear to form a unique structure known as the beta spiral which possesses elastometric properties. Inside the hydrophobic areas repeating sequences such as the pentapeptide pro-gly-val-gly-val have been observed the exact significance of which is not appreciated, but it appears to be well-conserved between species. Recent studies in the molecular biology of this protein have indicated that it is synthesized on the rough ER with a short leader sequence of about 25 residues. This is lost before the tropoelastin is exported. Diversity in sequence studies in these leaders suggest that there may be two elastins, type A and B, which vary with the maturation of the animal.
在过去18年里，人们付出了巨大的研究努力，深入探究了弹性纤维的结构。这始于对弹性蛋白中锁链素交联的阐明以及对源自缺铜动物的弹性蛋白前体原弹性蛋白的描述。对前体物质的表征表明，它是一条由大约800个氨基酸残基组成的单多肽链，其中赖氨酸残基成簇分布，注定要形成锁链素交联。该分子包含大片疏水序列，其间穿插着较短的聚丙氨酸链段和赖氨酸。较短的结构可能折叠成α螺旋。较大的疏水区域似乎形成了一种独特的结构，称为β螺旋，具有弹性特性。在疏水区域内观察到了重复序列，如五肽脯氨酸 - 甘氨酸 - 缬氨酸 - 甘氨酸 - 缬氨酸，其确切意义尚不清楚，但在不同物种之间似乎保存得很好。最近对这种蛋白质的分子生物学研究表明，它是在糙面内质网上合成的，带有一段约25个残基的短前导序列。在原弹性蛋白输出之前，这段前导序列会丢失。对这些前导序列的序列研究中的多样性表明，可能存在两种弹性蛋白，即A型和B型，它们会随着动物的成熟而变化。
