Fig. 6.

Dephosphorylation of a larger protein substrate by 14WM9. The 91-mer protein derived from prochlorosin ProcA2.8 and ending with ...CAAY^PAA at its C terminus was dephosphorylated by 14WM9, digested in-gel by Lys-C, and analyzed by MALDI MS (Experimental Procedures gives details). Dephosphorylation conditions: 100 µM 14WM9, 125 µM DNA anchor oligonucleotide, 20 µM protein, 70 mM Hepes (pH 7.5), 6 mM ZnCl₂, 40 mM MgCl₂, 20 mM MnCl₂, and 150 mM NaCl at 37 °C for 36 h. Y^OH product Lys-C fragment [M+H]⁺ m/z calculated 3,751.725, found 3,751.699, Δ = –6.9 ppm. Difference between product and substrate due to dephosphorylation Δ(m/z) calculated 79.966, found 79.993, Δ = +0.033%.