Antinutritive bases of resistance

A brief discussion of the chemical reactivity of the products of these enzymes is central to our proposed use of these enz)nnes as antinutritive bases of resistance. Polyphenol oxidase (PPO) and peroxidase (POD) oxidize phenolics to quinones, which are strong electrophiles that alkylate nucleophilic functional groups of protein, peptides, and amino acids (e.g., -SH, -NHof -HN-, and -OH)(Figure 1)(53,63-65). This alkylation renders the derivatized amino acids nutritionally inert, often reduces the digestibility of protein by tryptic and chymotryptic enzymes, and furthermore can lead to loss of nutritional value of protein via polymerization and subsequent denaturation and precipitation (63,66-69). POD is also capable of decarboxylating and deaminating free and bound amino acids to aldehydes (e.g., lysine, valine, phenylalanine. 

Our knowledge of how to most effectively utilize PPO, POD, and LOX as antinutritive bases of resistance against noctuid larvae is insufficient. A number of other critical enzymatic and chemical... 

Our evidence supports the contention that plant oxidative enzjnmes can be used as constitutive and/or inducible antinutritive bases of resistance against insects. This resistance is based on the irreversible chemical degradation of multiple essential or limiting nutrients, which may be more difficult for the insect species to evolve biochemical resistance against than against classical "toxins". 

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See also in sourсe #XX -- [ ]

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