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Generality and specificity of the binding behaviour of lysozyme with pectin varying in local charge density and overall charge
- Source :
- Food Hydrocolloids, 99:105345. Elsevier
- Publication Year :
- 2020
- Publisher :
- Elsevier, 2020.
-
Abstract
- We examined the similarities and differences of the binding behavior of lysozyme (lys) with pectin varying in local charge density (blockwise distribution and statistical distribution of methoxyl groups, BP and SP) and similar degree of methoxylation (DM). The interaction at ionic strength I = 0.01 and pH 5.1 was found to be mainly electrostatic, associated with an exothermic enthalpy change. BP which is more inclined to self-association binds lys forming strongly associated complex particles with average sizes much larger (10–20 μm) than that of SP. The latter formed with lys small (0.6–3 μm) complex particles or liquid droplets depending on DM. The critical Iset and pHset values for BP/lys systems, above which complexes do not form, are not sensitive to DM (approximately 0.1 and 11.5 respectively), whereas for SP/lys systems the critical Iset and pHset values decrease significantly with increasing DM. The effect of I on complexation (CP) of lys with BP and SP has a nonmonotonic character. The distribution of BP and SP within the complex particles is irregular and is different for pectin with low and high DM values. The binding constant and stoichiometry ratio (lys/pectin) of the systems with SP are slightly higher than those of BP at the same DM, and these values decrease sharply (50 times) with increasing DM. The large positive changes in entropy in SP/lys systems suggest that the interactions in these systems tend to be more hydrophobic in character at high DM. On the other hand, with BP, a negative enthalpy change, especially for pectin with low charge, suggests the formation of a large quantity of hydrogen bonds or van der Waals interactions during CP. ispartof: FOOD HYDROCOLLOIDS vol:99 status: published
- Subjects :
- POTENTIOMETRIC TITRATION
WHEY PROTEINS
food.ingredient
Pectin
ISOTHERMAL TITRATION CALORIMETRY
General Chemical Engineering
Enthalpy
Lysozyme
01 natural sciences
COMPLEX COACERVATION
chemistry.chemical_compound
0404 agricultural biotechnology
food
0103 physical sciences
BOVINE SERUM-ALBUMIN
Science & Technology
010304 chemical physics
Chemistry
Hydrogen bond
Charge density
Structure
Isothermal titration calorimetry
04 agricultural and veterinary sciences
General Chemistry
ITC
040401 food science
Binding constant
BETA-LACTOGLOBULIN
LIGHT-SCATTERING
Chemistry, Applied
Confocal microscopy
Crystallography
CITRUS PECTIN
Ionic strength
Food Science & Technology
Physical Sciences
IONIC-STRENGTH
Complexation
Life Sciences & Biomedicine
MONTE-CARLO SIMULATIONS
Food Science
Subjects
Details
- Language :
- English
- ISSN :
- 0268005X
- Database :
- OpenAIRE
- Journal :
- Food Hydrocolloids, 99:105345. Elsevier
- Accession number :
- edsair.doi.dedup.....263d2a5848cb047eec86c3cba020f837