Starch Debranching Enzyme Activity and Its Effects on Some Starch Physicochemical Characteristics in Developing Substituted and Complete Triticales (XTriticosecaleWittmack)

Pullulanase (EC 3.2.1.41) is a well known starch-debranching enzyme that catalyzes the cleavage of α-1,6-glycosidic linkages in α-glucans such as starch and pullulan. Crystal structures of a type I pullulanase from Paenibacillus barengoltzii (PbPulA) and of PbPulA in complex with maltopentaose (G5), maltohexaose (G6)/α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD) were determined in order to better understand substrate binding to this enzyme. PbPulA belongs to glycoside hydrolase (GH) family 13 subfamily 14 and is composed of three domains (CBM48, A and C). Three carbohydrate-binding sites identified in PbPulA were located in CBM48, near the active site and in domain C, respectively. The binding site in CBM48 was specific for β-CD, while that in domain C has not been reported for other pullulanases. The domain C binding site had higher affinity for α-CD than for G6; a small motif (FGGEH) seemed to be one of the major determinants for carbohydrate binding in this domain. Structure-based mutations of several surface-exposed aromatic residues in CBM48 and domain C had a debilitating effect on the activity of the enzyme. These results suggest that both CBM48 and domain C play a role in binding substrates. The crystal forms described contribute to the understanding of pullulanase domain–carbohydrate interactions.

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Purification and Molecular Genetic Characterization of ZPU1, a Pullulanase-Type Starch-Debranching Enzyme from Maize

PLANT PHYSIOLOGY ◽

10.1104/pp.119.1.255 ◽

1999 ◽

Vol 119 (1) ◽

pp. 255-266 ◽

Cited By ~ 63

Author(s):

Mary K. Beatty ◽

Afroza Rahman ◽

Heping Cao ◽

Wendy Woodman ◽

Michael Lee ◽

...

Keyword(s):

Genetic Characterization ◽

Molecular Genetic ◽

Debranching Enzyme ◽

Starch Debranching Enzyme ◽

Molecular Genetic Characterization

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In vitro pullulanase activity of wheat (Triticum aestivum L.) limit-dextrinase type starch debranching enzyme is modulated by redox conditions

Journal of Cereal Science ◽

10.1016/j.jcs.2007.04.015 ◽

2008 ◽

Vol 47 (2) ◽

pp. 302-309 ◽

Cited By ~ 13

Author(s):

Anne Repellin ◽

Monica Båga ◽

Ravindra N. Chibbar

Keyword(s):

Triticum Aestivum ◽

Triticum Aestivum L ◽

Redox Conditions ◽

Debranching Enzyme ◽

Limit Dextrinase ◽

Starch Debranching Enzyme

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Modified Methods in Starch-Based Biodegradable Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.183-185.1635 ◽

2011 ◽

Vol 183-185 ◽

pp. 1635-1641 ◽

Cited By ~ 5

Author(s):

Jun Feng Su ◽

Jian Jun Cheng

Keyword(s):

Mechanical Treatment ◽

Packaging Material ◽

Cross Linking ◽

Attractive Alternative ◽

Biodegradable Films ◽

Debranching Enzyme ◽

Renewable Source ◽

Physical Chemical ◽

Plastic Materials ◽

Starch Debranching Enzyme

With plastics resistance to degradation in nature and lack of effective recycling practice, it has resulted in a serious threat to the environment. Concerns about the environmental pollution caused by plastics have led to serious demands for biodegradable plastic materials made from renewable source. Starch is a biopolymer that has been being an attractive alternative for packaging material. A general overview on the microstructures of starch is given in this essay. The modified methods in biodegradable starch-based films are reviewed, which include physical, chemical and enzymic modification. Physical modification involves ultrasonic, mechanical treatment and addition of additives, such as plasticizer and coupling agent. Chemical modification consists of etherification, esterification, cross-linking, grafting and oxidation. Enzymic modification includes debranching reaction of starch debranching enzyme which contains pulullanase and isoamylase. The biodegradation of starch-based films and the prospects of their future are also detailed.

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