FIG 4.

Collision-induced dissociation γ-butyrobetainyl-CoA. (A) Extracted ion chromatograms correspond to the protonated form ([M+H]⁺) of γ-butyrobetainyl-CoA at m/z 895.2222 (5-ppm accuracy). (B) Collision-induced dissociation tandem mass spectra (25% normalized collision energy). (1) γ-Butyrobetainyl-CoA from the metabolome of GBB-grown cells. (2) Enzymatic formation of γ-butyrobetainyl-CoA analyzed after 60 min in 100 μl of Tris-HCl 100 mM (pH 8.0) containing 2.7 μg of BcoA/B, 5 mM GBB, 200 μM CoA, 2 mM ATP, and 10 mM MgCl₂. LC-MS analyses were conducted in the positive ionization mode.