Figure 2

2-AB is synthesized via the cysteine metabolism pathway.

(a) Structural formula of 2-AB and cysteine. (b) Schematic of cysteine metabolism pathway. (c) 2-AB production from 2-OBA. 2-OBA was incubated with glutamic acid and AST for 30 minutes. The reaction was stopped by adding HCl. GC-MS was used to measure 2-AB yield. (d) Intracellular 2-AB levels in H9c2 cells treated with ethyl 2-OBA. Cells were incubated with 1 mM or 5 mM ethyl-OBA for 1 h. After the incubation, the levels of 2-OBA and 2-AB were analyzed with GC-MS. Data are presented as the mean ± standard deviation (s.d.) of two independent experiments. *P < 0.05, ***P < 0.001. P-values were determined by ANOVA with Tukey’s multiple comparisons post-test. (e) Decreased 2-AB production in H9c2 cells treated with AOA, an inhibitor of AST. Cells were preincubated with 1 mM AOA for 1 h and incubated with 1 mM ethyl 2-OBA. The levels of 2-AB and 2-OBA were determined with GC-MS. Data are presented as the mean ± standard deviation (s.d.) of two independent experiments. **P < 0.01. n.s., not significant. P-values were determined by ANOVA with Tukey’s multiple comparisons post-test. A.U., arbitrary units; CBS, cystathionine beta synthase; CSE, cystathionine gamma lyase; 2-OBA, 2-oxobutyric acid; AOA, aminooxyacetic acid; AST, aspartate aminotransferase.