Effect of chitosan and chitin on the separation of membranes from proteins solubilized by pH shifts using cod (Gadus morhua).
Studies with isolated membranes and isolated membranes suspended in muscle proteins solubilized at pH 3 showed that mixing chitosan and membranes at this low pH followed by a pH adjustment to 10.5 could sediment membranes effectively at 4000 g. In the solubilized muscle homogenate, the effectiveness of membrane removal by chitosan at 4000 g for 15 min was molecular weight dependent. About 80% of the phospholipids and 28% of proteins were sedimented from solubilized muscle homogenate by mixing muscle homogenate (10 g of muscle tissue homogenized with 90 mL of distilled water) with 10 mL of MW 310-375 k chitosan (10 mg/mL in 0.1 N HCl) before solubilizing it at pH 10.5, whereas 55% of the phospholipids and 12% of proteins were sedimented by mixing muscle homogenate with the MW 310-375 k chitosan before solubilizing the homogenate at pH 3. Low molecular weight chitosans (at MW 1k or 33k) showed little effect on membrane sedimentation under the same conditions. Chitin was not useful for removing membranes at either pH 3 or 10.5, whether added before or after pH adjustment.
Liang
Yong
Y
Massachusetts Agricultural Experiment Station, Department of Food Science, University of Massachusetts/Amherst, Marine Station, Gloucester, Massachusetts 01930, USA. yliang@ufl.edu
Hultin
Herbert O
HO
Kim
Se-Kwon
SK
D000818:Animals; D002462:Cell Membrane / Q000737:chemistry*; D002498:Centrifugation; D002686:Chitin / Q000494:pharmacology*; D048271:Chitosan / Q000494:pharmacology*; D048389:Gadus morhua; D006863:Hydrogen-Ion Concentration; D008563:Membrane Lipids / Q000302:isolation & purification; D009124:Muscle Proteins / Q000302:isolation & purification*; D009132:Muscles / Q000648:ultrastructure; D012995:Solubility
D008563:Membrane Lipids; D009124:Muscle Proteins; D002686:Chitin; D048271:Chitosan