Spore wall protein involved in the adhesion to host cells surface glycoaminoglycans (GAGs). Microsporidian spore adherence is an integral part of activation and host cell infection. Localizes also at the anchoring disk complex which consists of the polar sac and the anchoring disk, playing a crucial role in the rupture of the spore wall and the subsequent release of the polar tube following activation. Heparin-binding motifs (HBM) are characterized by an XBBXBX or XBBBXXBX sequence, where X is any neutral amino acid and B is a positively charged basic amino acid, and are defined as the consensus sequence necessary for protein-heparin interactions. HBM motifs may be involved in spore adherence to host cells.