Glutaraldehyde lysine residues activation

The first reported preparation of cross-linked enzyme crystals was by Quiocho and Richards in 1964 [1], They prepared crystals of carboxypeptidase-A and cross-linked them with glutaraldehyde. The material they prepared retained only about 5% of the activity of the soluble enzyme and showed a measurable increase in mechanical stability. The authors quite correctly predicted that cross-linked enzyme crystals, particularly ones of small size where the diffusion problem is not serious, may be useful as reagents which can be removed by sedimentation and filtration. Two years later the same authors reported a more detailed study of the enzymic behavior of CLCs of carboxypeptidase-A [2], In this study they reported that only the lysine residues in the protein were modified by the glutaraldehyde cross-linking. The CLCs were packed in a column for a flow-through assay and maintained activity after many uses over a period of 3 months. 

HBsAg) and 90% reduction in core antigen (HBcAg) activity [151]. These results were superior to those obtained with formaldehyde, and the authors proposed that glutaraldehyde should be used for disinfection of items exposed to HBV in place of formaldehyde or hypochlorite solutions. However, the authors did point out that more direct approaches to determine viral in-fectivity after exposure were required. The aldehyde is thought to interact with lysine residues present on the most exposed structural protein of hepatitis A virus [152] and it is feasible that this interaction occurs also with HBV. 

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