Proteinaceous inhibitors of carbohydrate‐active enzymes in cereals: implication in agriculture, cereal processing and nutrition

Abstract

Enzymes that degrade, modify, or create glycosidic bonds are involved in carbohydrate biosynthesis and remodelling. Microbial carbohydrate-active enzymes form the basis of current green technology in the food, feed, starch, paper and pulp industries and the revolution in genomics may offer long-term gains on the quality and quantity of the raw materials. Proteinaceous inhibitors of carbohydrate-active enzymes (α-amylase, limit-dextrinase, polygalacturonase, pectin lyase, pectin methylesterase, invertase and xyloglucan endoglucanase) naturally occur in plants where they are involved in various roles from plant defence to metabolism. Xylanase inhibitors represent the latest addition to this growing family. In this review, we will focus on the inhibitors of carbohydrate-active enzymes present in cereals, mostly represented by α-amylase and xylanase inhibitors, and summarise the existing knowledge on their structure, function, and implication in cereal processing, agriculture and nutrition.

A Review: The Role of Barley Seed Pathogenesis-Related Proteins (PRs) in Beer Production

“…Generally, barley grain inhibitors have been classified as members of the PR-6 family. In addition, protease inhibition activity can be ascribed to ns-LTPs (PR-14), while α-amylase inhibition activity to TLP (PR-5) and γ-thionins (PR-12) 88,89,147 .…”

“…The α-amylase inhibitors from cereal seeds could decrease starch hydrolysis, thus affecting malting and brewing 89,145,147 . The bifunctional α-amylase/subtilisin inhibitor (BASI) could form a complex with barley α-amylase.…”

“…PRs also have an impact on beer colloidal haze 77,135,136 . Also, PRs may influence the degradation of complex molecules, such as proteins and carbohydrates, during malting and mashing 88,89 . In addition, PRs are among the most important beer components in respect to beer effect on consumer health 60 .…”

A Review: Biological and Technological Functions of Barley Seed Pathogenesis-Related Proteins (PRs)

“…A database for plant PIs is accessible at http://bighost.area.ba.cnr.it/ PLANT-PIs 261 . Several reviews on mode of action, structure and function of protease and/or α-amylase inhibitors have recently been published 95,116,117,162,178,224,254,326 .…”

“…The family of bifunctional inhibitors, able to suppress trypsin and exogenous α-amylase, were originally known as CM proteins based on their solubility in a chloroform and methanol mixture, although they are soluble in water or alcohol solutions as well. They are also referred as protease inhibitors of "cereal type" 162,254,326 . CMs inhibit exogenous α-amylases from many different sources, such as insect trypsin and other serine proteases.…”