The interaction of glutaraldehyde with poly(α,L‐lysine), n‐butylamine, and collagen. II. Hydrodynamic, electron microscopic, and optical investigations on the reaction products

Abstract

SynopsisInteractions of glutaraldehyde with either n-butylamine, poly(a,L-lysine), or collagen resulted in a fast release of protons in dilute aqueous solutions a t various pH values, followed by much slower changes. The latter reactions, which extended over hours and days, were followed spectrophotometrically and revealed the formation of distinct absorption bands in the visible and near-ultraviolet regions in all the above systems. The visible-range bands disappeared upon treatment with sodium borohydride. A qualitative relationship between oxygen uptake by the system n-butylamine-glutaraldehyde and the slow formation of colored products has been established, while the chemical nature of the reaction products has not been determined.Sedimentation velocity, viscosity, and optical rotation measurements on the products of interaction between poly(L-lysine) and glutaraldehyde in aqueous solution indicated large conformational changes in the polyamino acid present in excess (in residues) over the dialdehyde. In particular, the intrinsic viscosity dropped considerably after interaction, indicating intramolecular crosslinking. At molar ratios of 1:1 between polylysine residues and aldehyde groups, intermolecular crosslinking of polylysine was obtained a t pH 8.6.Electron microscopic examidations of collagen samples treated by glutaraldehyde a t various pH values indicated changes from unordered to more ordered structures upon treatment with glutaraldehyde, in particular a t pH 10.The present structural and optical investigations are considered to be relevant to tanning processes of hides and to fixation procedures.

Chemical Modifications of Heparin.1: Reaction of Partially N-Desulfated Heparin with Glutaraldehyde

“…HMMHEP showed extra bands near 265 and 235 nm in UV and CD spectra ( Figure 5). These bands were assigned to the aldol condensation products of glutaraldehyde in agreement with similar conclusions reported in the literature [10,11]. …”

“…In this paper, we wish to report the results of our investigations of heparin polymerization and/or crosslinking occurring when partially N-desulfated commercial heparin macromolecules are allowed to react with glutaraldehyde (GA), a difunctional aldehyde which is known to crosslink proteins by coupling with their primary amine groups in water [9][10][11][12]. The final goal of this study is to show the reactivity of the -NH2 groups present in partially N-desulfated heparin for further coupling of hydrophobic compounds.…”