- Large-scale preparation of α-D-(1→4)-oligogalacturonic acids from pectic acid
-
An efficient and inexpensive method for large-scale preparation of α-D-(1→4)-oligogalacturonic acids (oligo-GalA), up to DP 5, from pectic acid is described. Pectic acid was digested with a commercially available pectinase to yield a mixture of oligo-GalA, which was effectively separated by a combination of low-pressure - size-exclusion chromatography based on ion-exchange chromatography to obtain pure oligo-GalA of DP 2-5.
- Fan, Hong-Ni,Liu, Mei-Zheng,Lee, Yuan C.
-
p. 900 - 903
(2007/10/03)
-
- Some Properties of Endo-polygalacturonase from Trichosporon penicillatum SNO-3
-
Some properties of the endo-polygalacturonase from Trichosporon penicillatum were investigated.The enzyme showed the highest activity around pH 5.0 and was stable at this pH up to 50 deg C.The enzyme catalyzed the hydrolysis of galacturonic acid oligomers as well as its polymer.The pentamer was degraded to a trimer and a dimer, the tetramer to a trimer and a monomer, and the trimer to a dimer and a monomer, respectively, whereas the dimer was not degraded.The kinetic constant Vmax and Km values changed with the substrate chain-length; the Km values tended to decrease, whereas the Vmax values tended to increase with increasing chain-length of the substrate.The amino acid residue participating in the active site of the enzyme was studied and it was found to be histidine.
- Sakai, Takuo,Okushima, Minoru,Sawada, Masahiko
-
p. 2223 - 2232
(2007/10/02)
-
- THE MODE OF ACTION OF THE ISOLATED FORM OF TOMATO ENDO-D-GALACTURONANASE
-
The mode of action of the isolated form of tomato endo-D-galacturonanase of molecular weight close to 50 000 was investigated with oligo-D-galactosiduronic acids of polymerization degree 2 - 7 and their derivatives the terminal aldehyde group of which was reduced.The rate of hydrolysis,catalysed by this enzyme decreased with the shortening the chain length of oligo-D-galactosiduronates used; di(D-galactosiduronic) acid was not hydrolyzed by this enzyme at all.Tri(D-galactosiduronic) acid was cleaved into monomer and dimer, tetra(D-galactosiduronic) acid was alternatively cleaved into monomer and trimer, as well as into two dimers.The previously proposed conception that the binding site of the tomato endo-D-galacturonanase contains three subsites and that the catalytic groups are localized close to the first bond from the reducing end of the substrate segment bound in the complex were proved.The mode of hydrolysis of the reduced oligomers is in favour of the mentioned conception.
- Markovic, Oskar,Slezarik, Alexander
-
p. 525 - 531
(2007/10/02)
-