Figure 1.

Isoelectric focusing gel (negative image) of the salivary apyrase of L. longipalpis, indicating the basic nature of the enzyme. After the run, gels were exposed to 50 mM Tris⋅Cl, pH 8.3/0.1 M NaCl/20 mM CaCl₂/5 mM either ATP or ADP. Reaction was allowed to proceed for 30 min, allowing for calcium phosphate to precipitate, and was stopped by change to the above solution not containing nucleotide. Two pairs of homogenized salivary glands were used per lane.