Anusorn Cherdthong, PhD Applied Biochemistry in Nutritional Science E-learning: Enzymes

Introduction  Enzymes are protein--<activated reaction  Catabolism  Anabolism  Re-formation when end of reaction  Gain the products

Role of enzyne McDonald et al. (2011)

Type of enzymes  Simple protein: biological activity without nonprotein part  Conjugated protein or holoenzyme: biological activity with apoenzyme and cofactor

Classification of enzymes  Oxidoreductases  Transferases  Hydrolases  Lyases  Isomerases  Ligases  Synthase By The International Union of Biochemistry (IUB)

Classification of enzymes Oxidoreductases: addition/remove H atom  dehydrogenases  Oxidases  Peroxidases  Catalases  Oxygenases  hydroxylases  (Riis, 1983; McDonald et al., 2011)

Classification of enzymes Transferases: group transfer  Transaldolases  Transketolases, acyl, glucosyl  Phosphoryl transferases, kinases  Phosphomutases

Classification of enzymes Hydrolases: activation of hydrolysis  Esterasesglycosidases  Peptidases  Phosphatases  Thiolases  Phospholipases  Amidases  Deaminases  Ribonucleases

Classification of enzymes Lyases: on double bond  addition of water/ammonia/CO 2  Aldolases  Hydratases  Dehydratases  Synthases  Lyases

Classification of enzymes Isomerases: Group transfer to be an isomer  Racemases  Isomerases  mutases

Classification of enzymes Ligases or synthase: molecule formation with new bond  Pyruvate carboxylase

Property of enzymes  High specificity on substrate  All enzymes are protein ( da)  activate on native conformation  Activity of enzyme depend on amino acid group

Specificity enzymes McDonald et al. (2011) The lock and key theory Induced-fit theory

Factor affecting on enzymes  Temperate  pH  Concentration of enzyme  Concentration of substrate

Enzymes control  Nonactive form: pepsinogen etc  Covalent modification: add phosphory group into AA group  End product; inhibition on enzymes  Regulatory protein: calmodulin

Enzymes inhibitor  Irreversible inhibitor: iodoaceta mide  Reversible inhibitor  competitive inhibitor  noncompetitive inhibitor  uncompetitive inhibition

Enzymes in Animal nutrition  Amylase   -galactozidase  Cellulase  Pectinase  Protease  glucose oxidase  Calatase  Lipoxygenase

Conclusion Role of enzyme Classification of enzyme Enzyme activity and control

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