Collagenase induced changes in the circular dichroism spectrum of collagen

Abstract

SynopsisThe maximum at 220 nm in the circular dichroism spectrum of native collagen solution changed to a negative value after heat denaturation or collagenase hydrolysis. The enzyme induced rate of C1) change a t 220 nm was shown to be first order in collagen concentration. The specific rate constant k is actually a combined rate constant kfast and k,l,,v in which the ratio k,/k, is 4.1. The initial rates were linear with respect t o enzyme concentration, and the I<, was found to be 3.5 X 10-7 Ill. The rate of ultraviolet hyperchromicity at 220 nm on collagen hydrolysis was determined. The kf3't was the same as that obtained by C1).Both methods may be readily wed to assay for collagenase activity.The k,/k, ratio was 4.6.

Electro-spinning of pure collagen nano-fibres – Just an expensive way to make gelatin?

“…Further biophysical analysis of the nano-fibres in solutions showed extended denaturation of the triple-helical collagen, which is in agreement with a recent publication [30]. The CD spectra of the freeze-dried collagen preparations were consistent with the characteristic sinusoidal collagen triplehelical structure [74][75][76]. In contrast, HFP-recovered collagen and the electro-spun collagen originated scaffolds exhibited CD spectra indicating massive loss of triple-helical collagen [75]; or suggesting random coils similar to those obtained from gelatin [52,74,76] respectively.…”

“…The CD spectra of the freeze-dried collagen preparations were consistent with the characteristic sinusoidal collagen triplehelical structure [74][75][76]. In contrast, HFP-recovered collagen and the electro-spun collagen originated scaffolds exhibited CD spectra indicating massive loss of triple-helical collagen [75]; or suggesting random coils similar to those obtained from gelatin [52,74,76] respectively. When the same preparations were subjected to peptic digest, the CD spectra shifted to the left, indicating a non-triple-helical conformation, as has been observed with charged polypeptides, such as polylysine at low pH [76,77].…”

Nano-caged shikimate as a multi-site cross-linker of collagen for biomedical applications

“…It is important to note that natural collagen possesses a unique CD spectrum in the far UV region, with a small positive peak around 220 nm, a crossover at around 213 nm, and a large negative peak around 197 nm. 47,48 The results obtained for collagen scaffolds cross-linked with SCS nanoparticles showed a minimum negative peak at 197 nm and maximum positive peak at 221 nm with a cross over at 214 nm in the CD spectrum (Fig. 5), which are characteristic of the triple helical structure of collagen.…”

Preparation and characterization of two types of separate collagen nanofibers with different widths using aqueous counter collision as a gentle top-down process

“…Moreover, the intensities of the positive and negative peaks in the CD spectra of CNF100 at 100 MPa did not change significantly with the Pass numbers, whereas the corresponding intensities for CNF10 at 200 MPa increased with the increasing Pass number using the same sample collagen concentration. Previously, the ellipticity values of the collagen molecules at 220 nm have been reported to have a linear relationship with the collagen concentration [26]. Thus, decreases in the positive 220 nm maximum were assumed to reflect the disruption of the triple-fold helices.…”