A Sulfilimine Bond Identified in Collagen IV

Abstract

Toughing It Out in Membranes The formation of crosslinks in the triple-helical structure of collagen is crucial to its function. In the case of collagen IV, which provides structural integrity to the basement membrane of animal tissues, the chemical nature of the crosslinks has been difficult to pin down. Vanacore et al. (p. 1230 ) report a combination of high-resolution mass spectrometric and nuclear magnetic resonance studies that establish the crosslink between hydroxylysine-211 and methionine-93 is a sulfimine group (-S=N-). This type of bond appears to have evolved to withstand mechanical stress as animals evolved into more structurally complex organisms.