Skip to main content
Figure 2 | BMC Biochemistry

Figure 2

From: Comparative thermodynamic studies on substrate and product binding of O-Acetylserine Sulfhydrylase reveals two different ligand recognition modes†

Figure 2

Monitoring ligand binding by fluorescence spectroscopy. (A) Time dependent PLP fluorescence of OASS (1 μM) after addition of buffer, OAS (4 μM), methionine (1.4 mM), and cysteine (1.3 mM) as indicated in the figure. (B) Fluorescence quenching titrations of the St OASS with cysteine (closed circle) and methionine (open circle); the data from both sets were fit to two identical site model (eq 1) independently. The solid line represents the best fit to data that yields Kcysteine = 6.0 × 102 M-1; Kmet = 2.9 × 102 M-1; (C) OASS-cysteine (red) and OASS-met (Green) complexes superimposed to show the interaction of ligand in the active site. Methionine is covalently attached to the active site PLP through Schiff base.

Back to article page

BMC Biochemistry

ISSN: 1471-2091

Contact us