HPLC chromatographic traces (CHIRALPAK AY-H
column, λ = 280
nm) of β-etherase enzyme assay samples from cosubstrates racem-SβG and glutathione. Chromatographic regions
for vanillin (gray), Sβ(S)G (green), and Sβ(R)G (orange) peak elution times are highlighted by shading.
(A) No enzyme added, 0 h sample, where the ratio of peak area integrals
of Sβ(S)G to Sβ(R)G
was ∼1:1. After 1 h incubation with either enzymatic catalyst:
(B) NaLigE, (C) NsLigE, (D) SsLigE, (E) SsLigP, (F) NaLigF1, (G) NaLigF2,
or (H) SsLigF1. Structures of vanillin, Sβ(S)G, and Sβ(R)G are shown in Figure 1C. Abbreviations: Na, N. aromaticivorans strain DSM12444; Ns, Novosphingobium sp. strain
PP1Y; Ss, Sphingobium sp. strain SYK-6. See Experimental Section for details.