Pectinesterase

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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