One aspect of the present invention relates to the surprising discovery that modification of a glycan structure on a human SAP polypeptide can increase the biological activity of the SAP polypeptide relative to a corresponding sample of wild-type SAP isolated from human serum. The disclosure provides both variant human SAP polypeptides and methods for making the same. In particular, the present invention provides methods and compositions for in vitro and in vivo addition, deletion, or modification of sugar residues to produce SAP polypeptides, such as a human SAP polypeptide, having a desired glycosylation pattern.
