Purification of several pectin methyltransferases from cell suspension cultures of flax (Linum usitatissimum L.)

Citation
T. Bourlard et al., Purification of several pectin methyltransferases from cell suspension cultures of flax (Linum usitatissimum L.), CR AC S III, 324(4), 2001, pp. 335-343
Citations number
40
Categorie Soggetti
Multidisciplinary,"Experimental Biology
Journal title
COMPTES RENDUS DE L ACADEMIE DES SCIENCES SERIE III-SCIENCES DE LA VIE-LIFE SCIENCES
ISSN journal
07644469 → ACNP
Volume
324
Issue
4
Year of publication
2001
Pages
335 - 343
Database
ISI
SICI code
0764-4469(200104)324:4<335:POSPMF>2.0.ZU;2-A
Abstract
Three pectin methyltransferases (PMT5, PMT7, PMT18; EC 2.1.1.6.x) were solu bilized from the endo-membrane complex of flax cells, with 0.05 % Triton X- 100. After a 3 step-chromatography procedure, PMT7 and PMT5 were purified t o apparent homogeneity. PMT5 and PMT7 differed regarding their optimum pH ( 5 or 7), the methyl acceptor (low or highly methylesterified pectin), their focusing pH range (6-7 or 8-9) and relative molecular mass (40 +/- 5 or 11 0 +/- 10 kDa). SDS-PACE of PMT5 and PMT7 did not reveal bands at 40 or 110 kDa but only a silver stained band of about 18 kDa. Two independent methods (photo labelling and enzymatic activity) showed that this silver-stained b and corresponded to a methyltransferase with affinity For pectins. This pol ypeptide was of the same size as the enzyme designed PMT18 (18 +/- 3 kDa; p l 4-4.5) recovered during size exclusion chromatography of either PMT7 or P MT5, suggesting that PMT18 bears the catalytic site of PMT5 and PMT7. (C) 2 001 Academie des Sciences/Editions scientifiques et medicales Elsevier SAS.