... activity with kcat of 7.7 s )1 and Km of 0 .14 8 mmtoward shikimate, kcat of 7 .1 s )1 and Km of 0 .18 2 mm toward NADP, kcat of 5.2 s )1 and Km of 2.9 mm toward NAD. The optimum pH of theenzyme ... Asn86, Thr1 01, Asp102, and Gln244, in the substrate binding site of E. coli SDH(EcSDH) correspond to the Ser16, Ser18, Lys69,Asn90, Thr104, Asp105, and Gln237 in HpSDH.Asn149 and Arg150 of EcSDH ... proper-ties of HpSDH and the effects of pH and temperatureon HpSDH. The results show that HpSDH has a kcat of 7.7 ± 0.9 s )1 , Km of 0 .14 8 ± 0.028 mm and kcat⁄ Km of 5.2 · 10 4m )1 Æs )1 toward...