. Author manuscript; available in PMC: 2012 Feb 9.

Published in final edited form as: J Am Chem Soc. 2011 Jan 11;133(5):1553–1562. doi: 10.1021/ja109207m

Table 1.

Summary of deconvoluted protein masses observed in ESI-MS spectra of control and inactivated DDAH

DDAH preparation	Theoretical calc’d mass	Control incubations with no inactivator	Incubations with 1	Mass difference	Incubations with 11	Mass difference

	(Da)	observed mass (Da)^a	observed mass (Da) ^a	(Da)	observed mass (Da)	(Da)
Wild-type	30, 503	30, 498	30, 588	91	30,604	106
Denatured ^b	30, 503	ND^c	30, 497	1	ND	ND
C249S	30,487	30, 481	30, 481	0	ND	ND
H162G	30, 423	30, 418	30, 508	90	ND	ND
D66N	30, 502	30, 496	30, 496 ^d	0	30,604	108
			30, 586 ^d	90
E65Q	30, 502	30, 496	30,498	2	30, 496	0
D244N	30, 502	30, 497	30, 588	91	30, 603	106

The masses obtained from deconvoluted ESI-MS spectra are reported with errors of ± 10 Da.

Heat denatured wild-type DDAH

Not determined

The modified peak occurs at an approximate 2:1 peak intensity ratio with the unmodified peak.