3KCH:
reference: Revisiting glutaraldehyde cross-linking: the case of the Arg-Lys intermolecular doublet., Salem M, Mauguen Y, Prange T, Acta Crystallogr Sect F Struct Biol Cryst Commun. 2010 Mar 1;66(Pt, 3):225-8. Epub 2010 Feb 23. PMID: 20208148

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