Salt-induced inhibition of the precipitin reaction of concanavalin A with polysaccharides and glycoprotein.
The time course of the precipitin reactions of concanavalin A with glycogen, dextran and ovalbumin was investigated by a light-scattering method near 30 degrees C in 10 mM-Tris/HCl buffer, pH 7.4, containing neutral salts, i.e. NaCl, KCl, NaBr, KI and NaClO4. With 0.8 microM-lectin and 0.36 mg of glycogen/ml, the half-life, t 1/2, of the precipitin reaction was independent of salt concentration between 0.1 M and 1.5 M, and was the same (175s) in the presence of NaCl, KCl, NaBr and KI but was significantly (27%) higher in NaClO4. In contrast, the five salts caused significant to marked enhancement in t 1/2 for the reactions of concanavalin A with dextran and ovalbumin. Likewise, whereas the turbidity produced in 1 h as a result of lectin-glycogen precipitation remained unchanged, those measured for the binding of dextran and ovalbumin were decreased in the presence of three salts. The increase in t 1/2 and decrease in turbidity were found to be higher with NaClO4, followed by KI; NaBr produced moderate and NaCl (or KCl) small but generally significant inhibition of the precipitin reactions with dextran and ovalbumin. The results showed that the lectin-ligand precipitin reactions involve salt-sensitive polar interactions that are less pronounced with compactly folded ligands such as glycogen.
D001965:Bromides; D002704:Chlorates; D003208:Concanavalin A; D003911:Dextrans; D006003:Glycogen; D008024:Ligands; D010047:Ovalbumin; D011189:Potassium Chloride; D011193:Potassium Iodide; D011233:Precipitin Tests; D012492:Salts; D012964:Sodium; D012965:Sodium Chloride; D017670:Sodium Compounds; D013997:Time Factors
D001965:Bromides; D002704:Chlorates; D003911:Dextrans; D008024:Ligands; D012492:Salts; D017670:Sodium Compounds; D003208:Concanavalin A; D011193:Potassium Iodide; D012965:Sodium Chloride; D011189:Potassium Chloride; D006003:Glycogen; D010047:Ovalbumin; D012964:Sodium; C027938:sodium bromide; C032706:sodium chlorate