Histidinol dehydrogenase has been purified from a derepressed mutant of Escherichia coli B. A molecular weight of about 91000 was estimated by gel filtration. The native enzyme seems to be composed of two similar subunits which have a molecular weight of 52000 as determined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The pI of the enzyme as determined by isoelectric focusing is 4·75. The enzyme is maximally active at pH 9·5. It is highly specific for NAD+ and histidinol, with a Km (NAD+) of 0.57 mM and a Km (histidinol) of 14 m. Mn2+ is required for maximal activity. The enzyme is completely inactivated by 8 m-urea but regains its activity very quickly upon removal of the urea. Mn2+ and histidinol protect the enzyme from heat inactivation.
BitarK. G.,
FircaJ. R.,
LoperJ. C.1977; Histidinol dehydrogenase from Salmonella typhi-murium and Escherichia coli.
. Biochimica et biophysica acta 493:429–440
DhawaleM. R.,
CreaserE. H.,
LoperJ. C.1972; Evolutionary mechanism of adaptation of Arthrobacter histidinolovorans and Pseudomonas aeruginosa to use l-histidinol as a sole source of nitrogen and carbon. Journal of General Microbiology 73:353–358
JaenickeR. J.,
RudolfR.,
HeiderI.1979; Quaternary structure, subunits activity, and in vitro association of porcine mitochondrial malic dehydrogenase. Biochemistry 18:1217–1223
LindsayJ. A.,
CreaserE. H.1977; Purification and properties of histidinol dehydrogenase from psychrophilic, mesophilic and thermophilic bacilli. Biochemical Journal 165:247–253
MarangosP. J.,
ConstantinidesS. M.1974; Factors affecting the folding and association of flounder muscle glyceraldehyde-3-phosphate dehydrogenase in vitro.
. Biochemistry 13:904–914
MinsonA. C.,
CreaserE. H.1969; Purification of a trifunctional enzyme, catalysing three steps of the histidine pathway, from Neurospora crassa.
. Biochemical Journal 114:49–56
WeberK.,
OsbornM.1969; The reliability of molecular weight determinations by dodecyl sulphate-polyacrylamide gel electrophoresis. Journal of Biological Chemistry 244:4406–4412
YamatoS.,
MurachiT.1979; Dissociation and association of fumarase subunits with special reference to the formation of dehydrogenase from Salmonella typhimurium.
. European Journal of Biochemistry 93:189–195
YournoJ.1968; Composition and subunit structure of histidinol dehydrogenase from Salmonella typhimurium.
. Journal of Biological Chemistry 243:3277–3288
YournoJ.,
InoI.1968; Purification and crystalization of histidinol dehydrogenase from Salmonella typhimurium LT-2. Journal of Biological Chemistry 243:3273–3276