Enzyme and microorganism degrading rhamnogalacturonane II

Details Enzyme and microorganism degrading rhamnogalacturonane II Enzyme and microorganism degrading rhamnogalacturonane II

1998-01-26

2000-08-15

Lilling, Herbert J.

Chemistry: molecular biology and microbiology

Enzyme , proenzyme; compositions thereof; process for...

435 99, 435200, 4352563, C12N 924, C12N 120, C12N 900, C12P 1914

Patent

active

061035068

DESCRIPTION:

BRIEF SUMMARY
The present invention concerns an enzyme degrading rhamnogalacturonane II (RG II) and its derivatives and the method for obtaining said enzyme.
It further concerns a method for obtaining RG-II.
It also concerns the use of said enzyme.
Rhamnogalacturonane II is a universal and highly complex constituent of the cellular wall of plants (O'Neil et al., Methods in Plant Biochemistry (1990) 2:415-439)). It belongs to pectic polysaccharides and is mainly present in the average lamelle and the primary wall.
Its structure is extremely complex (FIG. 1) since it is composed of 12 different monosaccharides for one degree of polymerisation (dp) close to 30. This complexity is strengthened by the presence of rare sugars in its composition which contains apiose or 3-C-(hydroxymethyl)-D-glycero-tetrose, KDO or 2-ceto-3-deoxy-D-manno-octulosonic acid, DHA or 3-deoxy-D-lyxo-2-heptulosaric acid, 2-O-methyl-fucose, 2-O methyl-xylose and finally acetic acid or 3-C-carboxy-5-deoxy-L-xylose. This latter monosaccharide constitutes a specific marker of RG-II. More usual monosaccharides in parietal polysaccharides, rhamnose, fucose, arabinose, galactose and galacturnonic and glucuronic acids are also present in the composition of RG-II, but most often with anomeries and types of particular and multiple links which reinforce the specificity and complexity of the molecular structure.
The ultrastructural organisation of RG-II (FIG. 1) further increases this complexity (Puvanesarjah et al., Carbohydr. Res. (1991) 218:211-222)). A homologue chain composed of between 7 and 14 galacturonic acid residues linked at .alpha.-(1.fwdarw.4) carries at still not determined positions 4 different branches: two dissacharides and two more complex or nonsaccharide chains. Structural variabilities are observed for the length of the homogalacturonic chain and for the extremity of the branch B and seem due the enzymatical activities used to obtain it. Secondly, the presence of unidentified substituents has been detected on the A5 residue in addition, the RG-II molecule contains 2 to 3 methyl groups which esterify the carbolic groups of galacturonic acids and two acetyl groups situated on R3 (aceric acid) and B4 (2-O-methly-fucose) residues.
Thus, the structure of RG-II has been generally determined, even if the nature of certain substituents has still not been identified.
In the cellular wall of plants, RG-II is associated with native pectins, but the exact type of link between protopectin and RG-II is still unknown. Similarly, its role in the wall of vegetables is poorly known. However, it is known that it is present throughout the vegetation world (Albersheim et al., Biochem. Soc. Transactions (1994) 22:374-378); pteridophytes with spermotophytes, gymnosperms with angiosperms, monocotyledons with dicotyledons (FIG. 2) and in significant qualities in the average lamalla of the walls. It is also known that its structure is preserved in the different plants which have been studied (Albersheim et al., Biochem. Soc. Transactions (1994) 22:374-378)).
Recent studies have showed that it could act as a signal polysaccharide and induce specific responses from the plant (elicting activity) (Aldington and Fry, Exp. Botany (1994) 45:287-293). However, its abundance and omnipresence and complexity of its structure leave one to assume that it plays a fundamental role in the cohesion of the cellular walls of plants and thus in the cellular organisation of tissue systems.
RG-II is freed from the cellular walls under the action of enzymes with pectolytic activity (esterase pectin, endo- or exo-polygalacturonase) which degrade the smooth chains of native pectins and free RG-II in a non-degraded form (Darvill et al., Plant Physiol. (1978) 62:418-422), as shown on FIG. 1. The variability of the length of the homogalactronic chain accounts for the enzymatical degradations which have enable it to be freed from native pectins (Whitcombe et al., Carbohydr.Res (1995) 271:15-29).
The complexity and originality of the structure of RG-II render it particularly resistant to degrada

REFERENCES:
Stevenson et al Plant Physiol. (1986) 80, pp. 1012-1019, 1986.

Affiliated with

Also associated with

Rating

Enzyme and microorganism degrading rhamnogalacturonane II does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Enzyme and microorganism degrading rhamnogalacturonane II, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Enzyme and microorganism degrading rhamnogalacturonane II will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2005281