Proteinaceous α-amylase inhibitors: purification, detection methods, types and mechanisms

Abstract

α-Amylase is abundant in plants and animals. α-Amylase inhibitors can reduce endogenous α-amylase activity, playing an essential role in agricultural pest control, and preventing and treating human disease. In the agricultural field, α-Amylase inhibitors can restrict pest that relies on the starch of crops. Acarbose is an α-amylase inhibitor used to treat diabetes. Some αamylase inhibitors are represented by antinutritional factors, while others are proteinaceous. Depending on their structures and sources, researchers have divided them into seven types: The knottin-like type, the γ-thionin-like type, the cereal type, the Kunitz type, the thaumatin-like type, and the lectin-like type. This paper introduces the methods for separating, purifying, and detecting proteinaceous α-amylase inhibitors while examining the structure and inhibition mechanism of several proteinaceous α-amylase inhibitors. Finally, it explores the potential applications of α-amylase inhibitors.

The impact of the soluble protein fraction and kernel hardness on wheat flour starch digestibility

“…The soluble proteinaceous α-AIs identified were consistent with findings in the research of Salt, Robertson, Jenkins, Mulholland, and Mills (2005). All proteinaceous α-AIs found in wheat flour extracts were categorised as cereal type or CM type (inhibitors found in chloroform/methanol extracts of wheat) α-AIs, expect the α-amylase/subtilisin inhibitor which was classified as a Kunitz type (H. Li, Zhou, Zhang, Fu, Ying, & Liu, 2021;Svensson et al, 2004).…”

“…The Kunitz type inhibitor - α-amylase/subtilisin inhibitor was widely found in cereals including barley, rice and wheat. Barley α-amylase/subtilisin inhibitor was the most studied which had been reported to specifically inhibits barley α-amylase 2 (H. Li et al, 2021; Svensson et al, 2004). The wheat α-amylase/subtilisin inhibitor has not been well studied, and it was reported to have 92% similarity to barley α-amylase/subtilisin inhibitor in amino acid sequences (Franco et al, 2004; Wisessing & Choowongkomon, 2012).…”

“…The α-amylase/trypsin inhibitors are actually a family of proteins (CM2, CM3 and CM16 were detected in this study), which inhibit α-amylases from both porcine pancreas and insects by binding to the active site of amylase, hindering contact between substrates and amylases and weakening the affinity of α-amylases to substrates (H. Li et al, 2021;Saxena, Iyer, & Ananthanarayan, 2010). The Kunitz type inhibitor -α-amylase/subtilisin inhibitor was widely found in cereals including barley, rice and wheat.…”

Metabolome and Whole-Transcriptome Analyses Reveal the Molecular Mechanisms Underlying Hypoglycemic Nutrient Metabolites Biosynthesis in Cyclocarya paliurus Leaves During Different Harvest Stages

“…The results showed that the α-amylase inhibitory effects of neochlorogenic acid and vanillic acid were significantly higher than those of the three phenolic acids reported above but were lower than that of acarbose (85.67%). An alpha-amylase inhibitor of acarbose is the dominant drug in the field of diabetes, but it also has some toxicity and side effects, such as diarrhea, abdominal pain, and abdominal discomfort ( 47 ). Therefore, it is necessary to search for α-amylase inhibitors in natural products.…”

Common bean (Phaseolus vulgaris L.) α‐amylase inhibitors as safe nutraceutical strategy against diabetes and obesity: An update review

“…Thus, α‐amylase represents the crucial step in the initiation of the process of digestion and absorption of dietary polysaccharides (Tangphatsornruang, Naconsie, Thammarongtham, & Narangajavana, 2005). Therefore it can be the target for specific enzyme inhibitors, allowing to reduce the rate of carbohydrate absorption, the real energetic intake after a meal, and the subsequent glycemic peak (de Sales et al, 2012; Li et al, 2021).…”