Table 2.

Enzyme activities detectable in crude extract, membrane fraction, or soluble protein fraction as a function of the growth substrate used

Enzyme assay	Substrate	Sp act (mkat [kg protein])−1 (SD) in extracts of cells grown with substrate:
		Acetate	Taurine	HT
Hpa/Tpaa	HT	—d	1.2 (0.2)	2.8 (0.5)
	Taurine	—	0.5 (0.3)	1.6 (0.5)
Tdhb	HT	—	0.1 (0.1)	0.6 (0.1)
	Taurine	—	4.2 (0.1)	1.0 (0.1)
Alda	Alanine	—	—	1.1 (0.2)
Xscc	Sulfoacetaldehyde	—	0.7 (0.1)	0.4 (0.1)

^aCrude extracts were used for the enzyme assays.

^bMembrane fractions were used for the enzyme assays.

^cSoluble fractions were used for the enzyme assays.

^d—, below detection limit (<0.1 mkat [kg protein]⁻¹).