Volume 2 Issue 12, December 2007

Mass spectrum resulting from the Glyco- copper-catalysed Huisgen cycloadditon reaction of SSβG-Aha43 (a β-Galactosidase mutant protein from Sulfolobus solfataricus with single azide tag) with GlcNAc-O-CH2-alkyne. This is an example of a site-selective protein glycosylation. Image is from the protocol by van Kasteren et al. Cover by Jessica Iannuzzi.