抄録
Partially purified antibody specific to the antitumor, O-6 branched β-(1→ 3)-D-glucan (WG), isolated from the cold alkali-extract of the fruiting body of Volvariella volvacea (Fukurotake) was obtained by immunization of rabbits with the conjugate of WG with bovine serum albumin (BSA). Hapten inhibition studies of the precipitation reaction of the antibody and the β-D-glucan with various (1→6)-linked and branched (1→3)-linked β-D-gluco-oligosaccharides showed that the antibody recognizes the sequence involving the non-reducing terminal glucosyl groups and possibly the branch points. The WG antibody also interacted with other branched β-(1→ 3)- D-glucans, but the reactivity differed depending on the degree of branching. In connection with the specificity of the antibody, the antibody to glucan polv alcohol (WG polyol), raised by immunization with WG polyol-BSA, recognized mainly the polyol groups in the side chains and a part of (1→3)-linked glucose residues in the main chain. In relation to the antitumor action of WG on mouse-implanted Sarcoma 180, the serum of the mouse, after 12-23hr intraperitoneal administration of WG, had potent antitumor activity in another group of tumor-bearing mice. When this serum was put onto the antibody-conjugated immunpadsorbent column, the tumor-inhibiting factor was mostly retained on the column, suggesting that the factor is closely related to the glucan or glucan conjugate. Thus, the antibody-conjugated affinity column was shown to be useful in studies of the mechanism of antitumor action.
