Purification and properties of a novel enzyme, trehalose synthase, from Pimelobacter sp. R48.
A novel enzyme, trehalose synthase, was purified from a cell-free extract of Pimelobacter sp. R48 to an electrophoretically homogeneous state by successive chromatographies on DEAE-Toyopearl 650, Butyl-Toyopearl 650, and Mono Q HR5/5 columns. The molecular weight of the enzyme was estimated to be 62,000 by SDS-polyacrylamide gel electrophoresis, and the enzyme had a pI of 4.6 by gel isoelectrofocusing. The enzyme catalyzed the conversion of maltose into trehalose by intramolecular transglucosylation. The enzyme also converted into maltose but was inactive on other saccharides. The N-terminal amino acid of the enzyme was serine. The optimum pH and temperature were pH7.5 and 20 degrees C, respectively. The enzyme was stable in the range of pH 6.0-9.0 and up to 30 degrees C for 60 min. The rate of conversion of maltose into trehalose was independent of the maltose concentration. The maximum yield of trehalose from maltose were 81.8%, 80.9%, and 76.7% at 5, 15, and 25 degrees C, respectively. The activity was inhibited by Cu2+, Hg2+, Ni2+, Zn2+, and Tris.
Nishimoto
T
T
Hayashibara Biochemical Laboratories, Inc., Okayama, Japan.
Nakano
M
M
Nakada
T
T
Chaen
H
H
Fukuda
S
S
Sugimoto
T
T
Kurimoto
M
M
Tsujisaka
Y
Y
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D005964:Glucosyltransferases / Q000737:chemistry / Q000302:isolation & purification*; D006031:Glycosylation; D006093:Gram-Positive Asporogenous Rods / Q000235:genetics*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D008970:Molecular Weight; D013379:Substrate Specificity; D013696:Temperature
D000596:Amino Acids; D005964:Glucosyltransferases; C099692:trehalose synthase