Table 2.

Rates of flavin semiquinone formation (k_f) and decay (k_d) during NADPH reduction of the free and cross-linked CLSS

The absorbance at 600 nm was followed after rapidly mixing each fully oxidized protein (∼10 μm) with excess NADPH (100 μm) at 10 °C, according to details under “Experimental procedures.” Values are the mean ± S.D. of 5–7 trials.

Enzyme	kf	kd
	s−1	s−1
CLSS, pH 9-treated	98.6 ± 4.5	24.7 ± 3.3
CLSS-BMOE	85.3 ± 3.2	18 ± 2.0
CLSS-BMB	72.9 ± 1.4	6.8 ± 1.9
CLSS-BMH	64 ± 3.8	4.5 ± 0.8
CLSS-BM(PEG)11	41 ± 3.6	1.7 ± 0.4
CLSS, DTT-treated	20.4 ± 2.2	10.9 ± 1.9