Pharmaceutical Sciences Faculty Publications

Title

A Sulfilimine Bond Identified in Collagen IV

Document Type

Article

Publication Date

9-4-2009

Journal Title

Science

ISSN

1095-9203

Volume

325

Issue

5945

First Page

1230

Last Page

1234

DOI

10.1126/science.1176811

PubMed ID

19729652

PubMed Central® ID

PMC2876822

Abstract

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.

Keywords

Amino acid sequence, collagen type IV, mass spectrometry, biomolecular, protein

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