胶原蛋白形成

稳定的标识符
R-HSA-1474290
类型
途径
物种
HOMO SAPIENS.
路径的位置
一般
胶原蛋白形成
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胶原蛋白是一种来自40多种人类基因的至少29种结构蛋白质(Myllyharju&Kivirikko 2004)。它是结缔组织的主要成分,以及哺乳动物中最丰富的蛋白质,占全身蛋白质含量的约25%至35%。胶原蛋白的一个定义特征是三聚体左手聚丙烯II型螺旋胶原区域的形成。这些区域内的包装通过存在最小的氨基酸,甘氨酸,在每个第三个残留物中,得到重复的基序甘氨酸甘氨酸X-Y,其中X通常是脯氨酸(Pro)和Y通常4-羟脯氨酸(4HYP)。Gly-pro-hyp是胶原蛋白最常见的三态(Ramshaw等人1998)。胶原蛋白肽链也具有非胶原域,具有具有共同链结构的胶原亚类。胶原蛋白原纤维主要在纤维组织中发现,如肌腱,韧带和皮肤。其他形式的胶原蛋白在角膜,软骨,骨,血管,肠道和椎间盘中丰富。在肌肉组织中,胶原蛋白是胚胎的主要成分,构成肌肉质量的6%。在食品和工业中使用的明胶是胶原蛋原,这是不可逆转地水解的。 On the basis of their fibre architecture in tissues, the genetically distinct collagens have been divided into subgroups. Group 1 collagens have uninterrupted triple-helical domains of about 300 nm, forming large extracellular fibrils. They are referred to as the fibril-forming collagens, consisting of collagens types I, II, III, V, XI, XXIV and XXVII. Group 2 collagens are types IV and VII, which have extended triple helices (>350 nm) with imperfections in the Gly-X-Y repeat sequences. Group 3 are the short-chain collagens. These have two subgroups. Group 3A have continuous triple-helical domains (type VI, VIII and X). Group 3B have interrupted triple-helical domains, referred to as the fibril-associated collagens with interrupted triple helices (FACIT collagens, Shaw & Olsen 1991). FACITs include collagen IX, XII, XIV, XVI, XIX, XX, XXI, XXII and XXVI plus the transmembrane collagens (XIII, XVII, XXIII and XXV) and the multiple triple helix domains and interruptions (Multiplexin) collagens XV and XVIII (Myllyharju & Kivirikko 2004). The non-collagenous domains of collagens have regulatory functions; several are biologically active when cleaved from the main peptide chain. Fibrillar collagen peptides all have a large triple helical domain (COL1) bordered by N and C terminal extensions, called the N- and C-propeptides, which are cleaved prior to formation of the collagen fibril. The intact form is referred to as a collagen propeptide, not procollagen, which is used to refer to the trimeric triple-helical precursor of collagen before the propeptides are removed. The C-propeptide, also called the NC1 domain, directs chain association during assembly of the procollagen molecule from its three constituent alpha chains (Hulmes 2002).

纤维形成的胶原蛋白是最常见和研究得最好的亚群。胶原纤维是胶原原纤维的聚集或束,而胶原原纤维本身是对生胶原复合物的聚合物,每一个都由三个被称为α链的多肽链组成。原胶原被认为是更大的胶原结构的亚单位。它们长约300 nm,直径1.5 nm,具有左旋三螺旋结构,并在胶原原纤维中扭曲成右旋螺旋状的“超级螺旋”。细胞外空间的原胶原自发聚合,末端有规律地交错(Hulmes, 2002)。在纤维胶原蛋白中,分子交错约67nm,单位为D,根据水合状态而变化。每个d周期包含略多于4个胶原蛋白分子,因此每个d周期重复的微原纤维都有一个横截面上包含5个分子的区域,称为“重叠”,以及一个只包含4个分子的区域,称为“间隙”。三螺旋在横截面上以六边形或准六边形排列,在间隙区和重叠区都是如此(Orgel et al. 2006)。胶原分子通过赖氨酸和羟赖氨酸侧链相互交联。这种交联是不寻常的,只出现在胶原蛋白和一种相关的蛋白质弹性蛋白中。

胶原蛋白的大分子结构多样。3组胶原蛋白与较大的胶原纤维相结合,作为稳定细胞外基质组织的分子桥梁。IV型胶原排列在真皮-表皮连接处和血管基底膜的交错网状结构中。VI型胶原形成独特的微纤维,称为珠状纤维。VII型胶原形成锚定原纤维。VIII型和X型胶原形成六边形网状结构。XVII型胶原蛋白是半脂质粒的组成部分,它与alpha6Beta4整合素、plectin和laminin-332复合(de Pereda et al. 2009)。最近有报道称,XXIX型胶原是一种假定的表皮胶原,在基底层上表达最高(Soderhall et al. 2007)。胶原原纤维/聚集体在不同的组织中以不同的组合和浓度排列,提供了特定的组织特性。在骨骼中,胶原三螺旋排列成平行的交错排列,在对端胶原亚基的两端有40 nm的缝隙,这可能是矿物成分羟基磷灰石(Ca10(PO4)6(OH)2)与一些磷酸盐的晶体沉积的成核位点。 Collagen structure affects cell-cell and cell-matrix communication, tissue construction in growth and repair, and is changed in development and disease (Sweeney et al. 2006, Twardowski et al. 2007). A single collagen fibril can be heterogeneous along its axis, with significantly different mechanical properties in the gap and overlap regions, correlating with the different molecular organizations in these regions (Minary-Jolandan & Yu 2009).

文献参考文献
PubMed ID 标题 杂志
7574488 胶原蛋白:分子生物学,疾病和治疗潜力

Prockop,DJ.Kivirikko,Ki

学生物化学为基础 1995年
19693541. 胶原蛋白

戈登,可哈恩,拉

细胞组织res. 2010
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