Restoring assembly and activity of cystathionine β-synthase mutants by ligands and chemical chaperones

Table 1 Intracellular concentrations of chemical chaperones and cystathionine β-synthase (CBS) ligands after 4-h exposure to Escherichia coli

Chaperones and ligands in SOB medium		Chaperones and ligands in E. coli, mmol/kg wet weight
Chaperones and ligands in SOB medium		- Addition	+ Addition
Chaperones	Glycerol 750 mmol/l	2.3	64.6
	Betaine 100 mmol/l	0.4	11.0
	Taurine 50 mmol/l	ND^a	8.4
CBS ligands	δ-ALA 0.5 mmol/l^b	Not measured
	L-serine 100 mmol/l	ND^a	ND^a
	SAM 1 mmol/l	0.05	0.05

SOB super optimal broth, δ-ALA δ-aminolevulinic acid, SAM S-adenosyl-L-methionine
^aND Not detected, below the detection limit −0.02 mmol/kg E. coli wet weight for taurine, 0.01 mmol/kg E. coli wet weight for serine
^bConcentrations of δ-ALA were not determined, as it was shown previously that addition of 0.3 mM δ-ALA to the growth medium increased heme content in the bacteria up to 50-fold (Kery et al. 1994).