Vanacore Roberto, Ham Amy-Joan L, Voehler Markus, Sanders Charles R, Conrads Thomas P, Veenstra Timothy D, Sharpless K Barry, Dawson Philip E, Hudson Billy G
Division of Nephrology, Department of Medicine and Center for Matrix Biology, Vanderbilt University, Nashville, TN 37232, USA.
Science. 2009 Sep 4;325(5945):1230-4. doi: 10.1126/science.1176811.
Collagen IV networks are ancient proteins of basement membranes that underlie epithelia in metazoa from sponge to human. The networks provide structural integrity to tissues and serve as ligands for integrin cell-surface receptors. They are assembled by oligomerization of triple-helical protomers and are covalently crosslinked, a key reinforcement that stabilizes networks. We used Fourier-transform ion cyclotron resonance mass spectrometry and nuclear magnetic resonance spectroscopy to show that a sulfilimine bond (-S=N-) crosslinks hydroxylysine-211 and methionine-93 of adjoining protomers, a bond not previously found in biomolecules. This bond, the nitrogen analog of a sulfoxide, appears to have arisen at the divergence of sponge and cnidaria, an adaptation of the extracellular matrix in response to mechanical stress in metazoan evolution.
IV型胶原蛋白网络是基底膜的古老蛋白质，存在于从海绵动物到人类的后生动物上皮组织之下。这些网络为组织提供结构完整性，并作为整合素细胞表面受体的配体。它们由三螺旋原体寡聚化组装而成，并通过共价交联，这是稳定网络的关键强化方式。我们使用傅里叶变换离子回旋共振质谱和核磁共振光谱表明，一个亚磺酰亚胺键（-S=N-）交联相邻原体的羟赖氨酸-211和蛋氨酸-93，这是一种以前在生物分子中未发现的键。这种键是亚砜的氮类似物，似乎出现在海绵动物和刺胞动物分化之时，是后生动物进化过程中细胞外基质对机械应力的一种适应性变化。
