Immunochemical Characterization of the Hyaluronic Acid-Hyaluronectin Interaction

The interaction between hyaluronic acid (HA) and hyaluronectin (HN) was analyzed by gel chromatography and by the effects of HA on the immunological precipitation of HN. This interaction led to formation of larger molecules, as shown by gel permeation. No inhibition of immune precipitation occurred in liquid phase after addition of HA, but the precipitates in unstained gels were rendered transparent, giving the appearance of inhibition. However, after staining of the gels the precipitates appeared normal. Moreover, a non-linear decrease of the diffusion rate in antibody-containing gel was observed as a function of HA concentration at HA:HN weight ratios of 0.75 x 10(-3) and higher. A faster movement during electrophoresis, depending on the HA:HN ratio, suppressed the precipitation line when tested by electrosyneresis and produced an increase in migration distance when tested by Laurell's electroimmunoassay. These results show that in the immunochemical detection and quantitation of NH by these techniques consideration should always be given to the amount of HA in the samples.