2017 Volume 64 Issue 8 Pages 429-436
We examined the hyaluronidase-inhibitory activity of rhamnan sulfate derived from Monostroma nitidum, cultivated in Kukamoto Prefecture. Rhamnan sulfate containing 20% (w/w) sulfate groups was used in this study, and Lineweaver-Burk analysis indicated a competitive inhibition mechanism. Rhamnan sulfate was desulfated or hyper-sulfated to obtain rhamnan sulfate preparations with different sulfate group contents (0.5, 7, and 41% (w/w)). Subsequently, we examined the hyaluronidase-inhibitory activity of rhamnan sulfate with different sulfate content. Consequently, the rate of hyaluronidase inhibition by rhamnan sulfate increased in a sulfate group content dependent manner. The mixture of rhamnan sulfate and hyaluronidase produced a whitish, opaque material. IR and 1H-NMR analyses identified the material as a rhamnan sulfate-hyaluronidase complex; the material is thought to have resulted from ionic interactions between the negative electric charge of the sulfate group and the positive electric charge of the lysine residues of hyaluronidase. In rhamnan sulfates with higher sulfate content, the formation yields of the complex increased and the degradation rates of hyaluronic acid in the complex-removed filtrate decreased. Thus, we presume that rhamnan sulfate and hyaluronidase form a water-insoluble complex through ionic interactions and that rhamnan sulfate inactivates hyaluronidase.
