Hydroxypropyl guar-borate interactions with tear film mucin and lysozyme.
The interactions of hydroxypropyl guar (HPG) with boric acid, lysozyme, and mucin were characterized by rheology, light scattering, electrophoresis, and isothermal titration calorimetry to help understand how HPG interacts with tear film components. Borate binds to guar under pH, temperature, and ionic strength conditions representative of those found in the eye. The HPG-borate complexes behave as anionic polyelectrolytes and thus interact with cationic lysozyme, a major tear film protein, whereas HPG-borate does not appear to bind to mucin, an anionic glycoprotein. The interactions of HPG, borate, lysozyme, and mucin can be explained by two physical interactions: (1) pH-dependent binding of borate to carbohydrates and (2) the electrostatic attraction of oppositely charged macromolecules.
Lu
Chen
C
Department of Chemical Engineering, JHE-136, McMaster University, Hamilton, Ontario, Canada L8S 4L7.
Kostanski
Leopold
L
Ketelson
Howard
H
Meadows
David
D
Pelton
Robert
R
D000818:Animals; D001881:Borates / Q000737:chemistry*; D002417:Cattle; D002645:Chickens; D005685:Galactans / Q000737:chemistry*; D005690:Galactose / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D046911:Macromolecular Substances; D008351:Mannans / Q000737:chemistry*; D008358:Mannose / Q000737:chemistry; D009077:Mucins / Q000737:chemistry*; D009113:Muramidase / Q000737:chemistry*; D053149:Plant Gums / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*; D011485:Protein Binding; D012542:Scattering, Radiation; D055672:Static Electricity
D001881:Borates; D005685:Galactans; D046911:Macromolecular Substances; D008351:Mannans; D009077:Mucins; D053149:Plant Gums; D011134:Polysaccharides; C519976:hydroxypropyl guar; C007894:guar gum; D009113:Muramidase; D008358:Mannose; D005690:Galactose