Pectinesterases

Pectinesterases.—An electrophoretically homogeneous preparation of polygalacturonase obtained from Botrytis cinerea also exhibited pectinesterase activity.  

The synthesis of pectinesterase and pectinolytic enzymes by Colletotrichum capsid has been investigated.  

Pectinesterases.—The pectinesterase activities in tomatoes stored at different temperatures have been determined. The level of activity is low in mature green fruit but increased rapidly at ca. 20 °C - but not at either 4 or 33 C. The storage-life of tomatoes kept at 33 °C for several days is increased, owing to suppression of the polygalacturonase activity. Multiple forms of the enzyme are responsible for the pectinesterase activity of tomatoes one of the forms has been characterized.  

The pectinesterase activity isolated from culture fluids of Botrytis cinerea was associated with a poly-D-galacturonase fraction, even after gel filtration and ion-exchange chromatography. Pectinesterase activity has been detected in cultures of Sphaeropsis malorum growing on apple tissues.  

5 -Nucieotidases.—Since the 5 -nucleotidase from Dictyostelium discoideum interacted with immobilized concanavalin A, it appears to be a glycoprotein. Pectinesterases.—The occurrence, formation, assay, purification, and specificities of pectinesterases have been reviewed. Pectinesterase activity was detected both in healthy and diseased onions Allium cepa), but not in cultures of the invading bacterium (Pseudomonas cepacia) Both the pectinesterase and poly-D-galact-uronate lyase activities of Clostridium multifermentans are associated with a single complex.  

Pectinesterase has been immobilized, with retention of activity, on a porous glass to which pendant benzoyl azide groups are attached.  

The taxonomy of the brown rot fungi (Monilinia species) has been related to their extracellular cell wall-degrading enzymes. Patterns of pectinesterase secreted by M. fructigena, M. fructicola, and M. laxa were studied by column isoelectric focusing. 

Two forms of pectinesterase, apparently similar in molecular weight but differing in charge and response to cation concentration, have been demonstrated in limes and oranges. In the orange, one form was located in the peel while the other was located within the segment covers and juice sacs. 

Three multiple forms of pectinesterase have been found in extracts and purified products from carrot. The enzymes (mol. wts. 2.7 x 10 ) were found to possess properties similar to those of tomato pectinesterase. 

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Expression of polygalacturonase and pectinesterase in normal and transgenic tomatoes. 

Figure 2 Pectinesterase activity in transgenic tomato finit. Activity is expressed as...

Figure 1. Pectinesterase activity in normal tomato fruit. Enzyme activity is exjM-essed as (ueq min gfwt)...

Hobson, G.E. (1963) Pectinesterase in normal and abnormal tomato finit. Biochemical Journal. 86. 358-365. 

Markovic,0 and Jomvall,H (1986) Pectinesterase The primary structure of the tomato enzyme. European Journal of Biochemistry. 158.455-462. 

Pressey,R and Avants,J.K (1972) Multiple forms of pectinesterases in tomatoes. Phytochemistry. 11. 3139-3142. 

Ray,J.,Knapp,J.,Grierson,D.,Bird,C and Schuch,W. (1988) Identification and sequence determination of a cDNA clone for tomato pectinesterase. European Journal of Biochemistry. 174. 119-124. 

Tucker,G. A.,Robertson,N.G. and Grierson,D. (1982) Purification and changes in activities of tomato pectinesterase isoenzymes. Journal of the Science of Food and Agriculture. 33. 396-400. 

Cations Increase Activity and Enhance Permeation of Pectinesterase in Ultrafiltration... 

The effect of pH and cation concentration on pectinesterase (PE) activation and permeation on 30 kD MWCO ultrafiltration (UF) membrane was evaluated. In order of increasing effectiveness, PE activity was stimulated by monovalent and divalent cations, poly amines and trivalent cations. A similar trend was observed for permeation on UF membranes. Cation addition and higher pH releases PE from an inactive complex, increases activity, and increases permeation. Higher cation concentration decreases activity and permeation. These results suggest a common mechanism is involved in PE activation and permeation. 

Thermostable pectinesterases (TSPE), operationally defined as activity that survives 5 min at 70°C, contribute most to cloud loss in juices at low temperatures and juice pH (26). The percentage of total activity that is thermostable is highly variable and differs in kinetic properties, (22, 26), ease of solubilization (28, 29), stability to low pH (25) and stability to freeze-thaw cycles (23). Some of the variability in reported total PE and TSPE may be related to limitations of current methods to quantify activity. Any processing treatment or assay condition that increases cell wall breakdown or release PE from a pectin complex would enhance detection of total and TS-PE activity. Commercially, PE is inactivated by pasteurization in a plate heat exchanger or during concentration in the TASTE evaporator. 

Evans, R. McHale, D. 1968. Multiple forms of pectinesterase in limes and oranges. Phytochemistry 17 1073-1075. 

Jansen, E.F. Jang, F. Bonner, J. 1960. Orange pectinesterase binding and activity. Food Research 25 64-72. 

Macdonald, H.M. Evans, R. Spenser, W.J. 1993. Purification and properties of the major pectinesterases in lemon fruits (Citrus limon). J. Sci. Food Agric. 62 163-168. 

Rouse, A.H. 1951. Effect of insoluble solids and particle size of pulp on the pectinesterase activity in orange juice. R. State Hort. Soc. Proc. 64 162-166. 

Rouse, A.H. 1953. Distribution of pectinesterase and pectin in component parts of citrus fruits. Food Technol. 7 360-362. 

Rouse, A.H. Atkins, C.D. 1955. Pectinesterase and pectin in commercial orange juice as determined by methods used at the Citrus Experiment Station. Florida Agric. Exper. Station Bull. 570 1-19. 

Seymour, T.A. Preston, J.F. Wicker, L. Lindsay, J.A. Marshall, M.R. 1991a. Purification and properties of pectinesterases of Marsh white grapefruit pulp. J. Agric. Food Chem. 39 1080-1085. 

Snir, R. Koehler, P.E. Sims, K.A. Wicker, L. 1995. pH and Cations Influence Permeability of Marsh Grapefruit Pectinesterase on Polysulfone Ultrafiltration Membrane. J. Agric. Food Chem. 43 1157-1162. 

Versteeg, C. 1979. Pectinesterases from the orange fruit - Their purification, general characteristic and juice cloud destabilizing properties. Ph.D. thesis. Agricultural Univ., The Netherlands. 

Versteeg, C. Rombouts, F.M. Spaansen, C.H. Pilnik, W. 1980. Thermostability and orange juice cloud destabilizing properties of multiple pectinesterases from orange. J. Food Sci. 45 969-973. 

Wicker, L. Vassallo, M. Echeverria, E. 1988. Solubilization of cell-wall-bound, thermostable pectinesterase from Valencia oranges. J. Food Sci. 53 1171-1174 and 1180. 

This study reports on the production of pectic enzymes and partial characterization of polygalacturonases produced by Candida boidinii. Candida boidinii belongs to the so called methylotrophic yeasts with famous utilization of methanol. Pectin, the natural substrate of pectic enzymes complex, can serve for microorganisms as a C - source by two different ways after deesterification with pectinesterase as methanol and after hydrolytic cleavage with... 

The activities of pectic enzymes present in cultivation medium (98 mg of protein extracted from 2.5 1 of pectin medium) were poor, not leading to the clarification of cultivation medium indicating the cleavage of pectate chains, with values 0.024 pmol/min.mg for polygalacturonase, 0.004 pmol/min.mg for exopolygalacturonase, 0.034 pmol/min.mg for pectinesterase and 0.005 pmol/min.mg for pectin lyase. The production of individual pectic enzymes was dependent on the C-source used in the cultivation medium (Tab. 1). 

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