Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) from the skin of striped catfish (Pangasianodon
hypophthalmus) were isolated and characterised. The yields of ASC and PSC were 5.1% and 7.7%,
based on the wet weight of skin, respectively, with the accumulated yield of 12.8%. Both ASC and PSC
comprising two different a-chains (a1 and a2) were characterised as type I and contained imino acid
of 206 and 211 imino acid residues/1000 residues, respectively. Peptide maps of ASC and PSC hydrolysed
by either lysyl endopeptidase or V8 protease were slightly different and totally differed from those of
type I calf skin collagen, suggesting some differences in amino acid sequences and collagen structure.
Fourier transform infrared (FTIR) spectra of both ASC and PSC were almost similar and pepsin hydrolysis
had no marked effect on the triple-helical structure of collagen. Both ASC and PSC had the highest solubility
at acidic pH. A loss in solubility was observed at a pH greater than 4 or when NaCl concentration
was higher than 2% (w/v). Tmax of ASC and PSC were 39.3 and 39.6 C, respectively, and shifted to a lower
temperature when rehydrated with 0.05 M acetic acid. Zeta potential studies indicated that ASC and PSC
exhibited a net zero charge at pH 4.72 and 5.43, respectively. Thus, ASC and PSC were slightly different in
terms of composition and structure, leading to somewhat different properties
Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) from the skin of striped catfish (Pangasianodon
hypophthalmus) were isolated and characterised. The yields of ASC and PSC were 5.1% and 7.7%,
based on the wet weight of skin, respectively, with the accumulated yield of 12.8%. Both ASC and PSC
comprising two different a-chains (a1 and a2) were characterised as type I and contained imino acid
of 206 and 211 imino acid residues/1000 residues, respectively. Peptide maps of ASC and PSC hydrolysed
by either lysyl endopeptidase or V8 protease were slightly different and totally differed from those of
type I calf skin collagen, suggesting some differences in amino acid sequences and collagen structure.
Fourier transform infrared (FTIR) spectra of both ASC and PSC were almost similar and pepsin hydrolysis
had no marked effect on the triple-helical structure of collagen. Both ASC and PSC had the highest solubility
at acidic pH. A loss in solubility was observed at a pH greater than 4 or when NaCl concentration
was higher than 2% (w/v). Tmax of ASC and PSC were 39.3 and 39.6 C, respectively, and shifted to a lower
temperature when rehydrated with 0.05 M acetic acid. Zeta potential studies indicated that ASC and PSC
exhibited a net zero charge at pH 4.72 and 5.43, respectively. Thus, ASC and PSC were slightly different in
terms of composition and structure, leading to somewhat different properties
การแปล กรุณารอสักครู่..
