. Author manuscript; available in PMC: 2019 Nov 26.

Published in final edited form as: J Nat Prod. 2018 Oct 23;81(11):2410–2418. doi: 10.1021/acs.jnatprod.8b00378

Table 3.

Masses of hCE1 determined by MS following incubation with different molecules.

Small molecule ID	Small molecule exact mass (m/z; Da)	Predicted mass of adducted moiety (Da)	Observed mass (Da)	Observed mass of adduct (Da)
None	NA^a	NA	61374 61537 61698	NA
4	310.12	311.13	61,686 61,845 62,008	312 308 309.8
PMSF	174.02	155.02	61,528 61,691 61,855	153.8 153.6 157.2
PMSF+4	PMSF = 174.02 4 = 311.13	Unknown^b	61,528 61,691 61,852	153.6 153.7 153.7
6	294.09	295.10	61662 61826 61980	288 289 282

– NA - Not applicable

– The product of the reaction of hCE1 with PMSF followed by 4 would either be ~155Da or 311Da (or potentially, 466 Da - 155+311) depending upon the reactivity of the enzyme with these small molecules.