Stability of pectinesterases of Marsh white grapefruit pulp

Seymour, Thomas A.; Preston, James F.; Wicker, Louise; Lindsay, James; Wei, Cheng; Marshall, Maurice R.

doi:10.1021/jf00006a014

Cited by 46 publications

(45 citation statements)

References 14 publications

(21 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The two isoforms of PME in yellow cedar seeds have the same molecular mass of 62 kD and different pIs of 8.7 and 8.9, similar to the pIs of other PME isoforms characterized so far (Bordenave and Goldberg, 1994;Alonso et al, 1997). The enzyme from yellow cedar showed considerable stability when stored at 4°C, although it is not as thermally stable as the PMEs found in some fruits (Versteeg et al, 1980;Seymour et al, 1991;Laratta et al, 1995). Yellow cedar PME was active over a wide pH range (between 7.4-11.0), somewhat similar to that of other PMEs in which the optimum pH range is 7 to 9 (Rexova-Benkova and Markovic, 1976).…”

Section: Discussionmentioning

confidence: 89%

An Increase in Pectin Methyl Esterase Activity Accompanies Dormancy Breakage and Germination of Yellow Cedar Seeds

2000

View full text Add to dashboard Cite

Pectin methyl esterase (PME) (EC 3.1.1.11) catalyzes the hydrolysis of methylester groups of cell wall pectins. We investigated the role of this enzyme in dormancy termination and germination of yellow cedar (Chamaecyparis nootkatensis [D. Don] Spach) seeds. PME activity was not detected in dormant seeds of yellow cedar but was induced and gradually increased during moist chilling; high activity coincided with dormancy breakage and germination. PME activity was positively correlated to the degree of dormancy breakage of yellow cedar seeds. The enzyme produced in different seed parts and in seeds at different times during moist chilling, germination, and early post-germinative growth consisted of two isoforms, both basic with isoelectric points of 8.7 and 8.9 and the same molecular mass of 62 kD. The pH optimum for the enzyme was between 7.4 and 8.4. In intact yellow cedar seeds, activities of the two basic isoforms of PME that were induced in embryos and in megagametophytes following dormancy breakage were significantly suppressed by abscisic acid. Gibberellic acid had a stimulatory effect on the activities of these isoforms in embryos and megagametophytes of intact seeds at the germinative stage. We hypothesize that PME plays a role in weakening of the megagametophyte, allowing radicle emergence and the completion of germination.

show abstract

Section: Discussionmentioning

confidence: 89%

An Increase in Pectin Methyl Esterase Activity Accompanies Dormancy Breakage and Germination of Yellow Cedar Seeds

2000

View full text Add to dashboard Cite

show abstract

“…The thermal inactivation of pepper PME at pH 7.5 in this temperature range exhibits a biphasic model, indicating the presence of a heat-labile and a heat-resistant fraction of PME, both showing first-order inactivation mechanisms. Labile and resistant forms of PME have been shown to occur in a number of other fruits and vegetables including oranges (18,31,32), grapefruits (33), sweet cherries (8), persimmon (9), tomatoes (28), and green beans (34). At the higher temperatures, the inactivation of the heat-labile fraction proceeds very quickly so that the inactivation rate constants cannot be accurately estimated.…”

Section: Purification Of Pepper Pectin Methylesterase By Affinitymentioning

confidence: 99%

Activity and Process Stability of Purified Green Pepper (Capsicum annuum) Pectin Methylesterase

Castro

Loey

Saraiva

et al. 2004

J. Agric. Food Chem.

View full text Add to dashboard Cite

Pectin methylesterase (PME) from green bell peppers (Capsicum annuum) was extracted and purified by affinity chromatography on a CNBr-Sepharose-PMEI column. A single protein peak with pectin methylesterase activity was observed. For the pepper PME, a biochemical characterization in terms of molar mass (MM), isoelectric points (pI), and kinetic parameters for activity and thermostability was performed. The optimum pH for PME activity at 22°C was 7.5, and its optimum temperature at neutral pH was between 52.5 and 55.0°C. The purified pepper PME required the presence of 0.13 M NaCl for optimum activity. Isothermal inactivation of purified pepper PME in 20 mM Tris buffer (pH 7.5) could be described by a fractional conversion model for lower temperatures (55-57°C) and a biphasic model for higher temperatures (58-70°C). The enzyme showed a stable behavior toward high-pressure/temperature treatments.

show abstract

“…The molecular mass ranged between 21 000 and 53000 daltons. Like many other cell wall proteins, PMEs can be glycosylated (Giovane et al 1990;Seymour et al 1991;Rillo et al 1992); and in one case, PME was reported to be a lipoprotein (Lee and MacMillan 1968). It has been proposed, and in part demonstrated (Seymour et al 1991), that these post-traductional modifications might increase PME stability.…”

Section: Physicochemical Propertiesmentioning

confidence: 99%

Analysis of Pectin Methyl Esterases

Bordenave¹

1996

Modern Methods of Plant Analysis

View full text Add to dashboard Cite

Stability of pectinesterases of Marsh white grapefruit pulp

Cited by 46 publications

References 14 publications

An Increase in Pectin Methyl Esterase Activity Accompanies Dormancy Breakage and Germination of Yellow Cedar Seeds

An Increase in Pectin Methyl Esterase Activity Accompanies Dormancy Breakage and Germination of Yellow Cedar Seeds

Activity and Process Stability of Purified Green Pepper (Capsicum annuum) Pectin Methylesterase

Analysis of Pectin Methyl Esterases

Contact Info

Product

Resources

About