Structural similarities among concanavalin A, haptoglobin, and trypsin

Abstract
Comparison of the primary structure of concanavalin A with those of trypsin and β (heavy) chain of haptoglobin revealed a significant degree of chemical similarity. The amino acid sequence of concanavalin A was found to be 53.6% related to trypsin and haptoglobin. Certain analogy in the tertiary structure was shown by the use of thionine binding to the specific active site, characteristic for serine proteases.