Two unexpected promiscuous activities of the iron–sulfur protein IspH in production of isoprene and isoamylene

Table 1 Enzyme tests with IspH

Substrate	Products in the headspace (ng/mL)			[2M2B]:[3M1B]
Substrate	Isoprene	2M2B	3M1B	[2M2B]:[3M1B]
DMAPP	+^a	39.1 ± 3.9	4.58 ± 0.6	8.5:1
IPP	–	–	–
HMBPP	21.6 ± 2.3	6.23 ± 1.1	0.83 ± 0.1	7.5:1

Values are presented as the average ± standard deviation of three independent experiments
The reaction was performed in 20 mM Tris–HCl buffer (pH 7.8) containing 150 mM NaCl at 37 °C for 1 h
^aTrace amount of isoprene, as was also observed in the negative control

ISSN: 1475-2859