The success of glutaraldehyde as a crosslinking agent is a result of its
multicomponent nature, where several forms are present in equilibrium in the reagent solution at a given pH. However, the exact molecular composition of glutaraldehyde solutions, as well as
which component is the most reactive, is debatable despite plenty of knowledge. As a result, the reaction mechanism of glutaraldehyde with protein amino groups is not clearly understood,
as illustrated by the large number of mechanisms reported in the literature and summarized in this review. No single mechanism seems to be responsible for glutaraldehyde crosslinking
with proteins. All reported forms of glutaraldehyde exhibit the ability to react and crosslink proteins, leading to the formation of a broad range of conjugates. A fairly rigid control of
reaction conditions is needed to achieve
efficient insolubilization of each different
enzyme due to their structural
variability. Nonetheless, the resulting
enzyme derivatives generally show
good stability and thus can be reused.
Although partial enzyme inactivation
due to chemical modification is often
unavoidable, in most cases enough
catalytic activity is retained. More work
is needed to provide additional information
on the exact structure of these
crosslinked products.