Protein adsorption to ceramic surfaces is an important early step in the function of implants. The types and amounts of adsorbed protein and the resulting conformational changes could mediate subsequent cell adhesion and inorganic deposition. Microporous silicoalumino-phosphates, which allow variations in surface composition within the same crystal structure, have been used as model surfaces. Effects of surface composition on adsorption isotherms, elutability, and biological activity of the adsorbed protein layer have been studied using lysozyme, a model protein. Control over protein adsorption mechanisms using well-characterized surface properties could be used to predict the biological properties of surfaces, and engineer coatings for a desired response.