N-(5-dimethylaminonaphthalene-1-sulfonyl)-3-aminobenzene boronic acid as an active-site-directed fluorescent probe of lipoprotein lipase.

Resonance energy transfer was used to monitor the interaction of an active-site-directed fluorescent inhibitor, N-(5-dimethylaminonaphthalene-1-sulfonyl)-3-aminobenzene boronic acid, and lipoprotein lipase (EC 3.1.1.34). The binding of this probe to the active site of lipoprotein lipase had an association constant, Ka, of 1.1 X 10(6) M-1, indicating a strong interaction. The binding was displaced competitively by benzene boronic acid. The method described provides a sensitive procedure to probe the active site of lipoprotein lipase.