High concentration of propanol does not significantly alter the triple helical structure of type I collagen

The effect of isopropyl alcohol (IPA) and n-propyl alcohol (PA) on collagen, the main component of the various connective tissues in animals, was analyzed to explore the solvent-induced polarity stress. Collagen precipitates in the presence of IPA and PA at concentrations (>50 %, v/v). The properties of precipitated collagen, after re-dissolving them in acetic acid solution, was investigated to understand (i) whether collagen precipitates induced by IPA and PA is in native or denatured form and (ii) the role of alkyl chain (linear and branched) in the solvent on the precipitation of collagen. Results demonstrate that precipitated collagen in both PA and IPA not only retains its triple helical structure but also maintains its thermal stability, fibrillation, and fluorescence properties as that of native collagen. The results also demonstrate that the nature of alkyl chain in the solvent has minor influence on the structural characteristics of collagen during precipitation.