Collagens
were extracted from
the
grass
carp skin and scale by the acid-enzyme combination
method. Their structural properties were analyzed by ultraviolet
spectrum (UV), sodium dodecyl
sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), fourier transform
infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). And the
self-assembly behavior of collagens were compared by turbidity experiment, detection
of fibril formation and scanning electronic microscopy
(SEM).The results indicated that collagens from grass carp skin and scale were
characterized as type I collagen , containing
two α-chains, and maintained a triple helix structure. Denaturation temperatures of the collagens from
scale and skin were 34.99 °C and 39.75 °C, respectively. The self-assembly curves showed that the collagens could self-assemble into fibrils at 30 °C near neutral pH with NaCl, and the self-assembly degree of collagens were similar (skin 28%,
scale 27.33%).
Scanning electronic
microscopyobservations suggested that both of the collagens
could form intertwine fibril network. The reticular fibrous structure of the
scale collagen was more obvious than skin collagen, and a periodic striped
D-band was observed. While the skin collagen fiber structure has a collapse and
no D-band.