Unknown

Dataset Information

0

A novel enzyme activity involving the demethylation of specific partially methylated oligogalacturonides.


ABSTRACT: Studies of the enzymic digestion of pectic substrates using different polygalacturonase (PG) preparations have revealed evidence for a previously unreported enzyme activity carried out by a contaminating enzyme in one of the preparations. This observed activity involves the demethylation of specific oligogalacturonides, namely 2-methyltrigalacturonic acid and 2,3-dimethyltetragalacturonic acid. However, no large-scale demethylation of highly methylated polymeric substrates is found, demonstrating that the enzyme responsible is not a conventional pectin methylesterase (PME). Furthermore, it has been shown that a commercial sample of fungal PME from Aspergillus niger demethylates all of the oligogalacturonides present as primary products of endo-PG digestion, in contrast with the activity observed here. On the basis of the known methyl ester distribution of the endo-PG-generated fragments and knowledge of which of these oligogalacturonides are demethylated, it is concluded that the observed activity can be explained by the existence of an exo-acting methylesterase that attacks the non-reducing end of the oligogalacturonide molecules.

SUBMITTER: Williams MA 

PROVIDER: S-EPMC1222889 | biostudies-other | 2002 Oct

REPOSITORIES: biostudies-other

Similar Datasets

| S-EPMC6161375 | biostudies-literature
| S-EPMC7640899 | biostudies-literature
| EGAS00001003157 | EGA
| S-EPMC6454695 | biostudies-literature
| S-EPMC6237784 | biostudies-literature
| S-EPMC7532633 | biostudies-literature
2023-08-04 | GSE210218 | GEO
2023-08-04 | GSE210219 | GEO
| S-EPMC2693314 | biostudies-literature