title: In silico structural characteristics and α-amylase inhibitory properties of Ric c 1 and Ric c 3, allergenic 2S albumins from Ricinus communis seeds.
abstract: The major Ricinus communis allergens are the 2S albumins, Ric c 1 and Ric c 3. These proteins contain a trypsin/α-amylase inhibitor family domain, suggesting that they have a role in insect resistance. In this study, we verified that Ric c 1 and Ric c 3 inhibited the α-amylase activity of Callosobruchus maculatus, Zabrotes subfasciatus, and Tenebrio molitor (TMA) larvae as well as mammalian α-amylase. The toxicity of 2S albumin was determined through its incorporation in C. maculatus larvae as part of an artificial diet. Bioassays revealed that 2S albumin reduced larval growth by 20%. We also analyzed the tridimensional structures of Ric c 1 and Ric c 3 by (a) constructing a comparative model of Ric c 1 based on Ric c 3 NMR structure and (b) constructing the theoretical structure of the Ric c 1-TMA and Ric c 3-TMA complexes. Our biological and theoretical results revealed that Ric c 1 and Ric c 3 are a new class of α-amylase inhibitors. They could potentially be used to help design inhibitors that would be useful in diverse fields, ranging from diabetes treatment to crop protection.
authors.affiliation: Laboratório de Química e Função de Proteínas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Rio de Janeiro, Brazil.
authors.forename: Viviane Veiga
authors.initials: VV
authors.lastname: Do Nascimento
authors.forename: Helena Carla
authors.initials: HC
authors.lastname: Castro
authors.forename: Paula Alvarez
authors.initials: PA
authors.lastname: Abreu
authors.forename: Antônia Elenir Amâncio
authors.initials: AE
authors.lastname: Oliveira
authors.forename: Jorge Hernandez
authors.initials: JH
authors.lastname: Fernandez
authors.forename: Jucélia Da Silva
authors.initials: Jda S
authors.lastname: Araújo
authors.forename: Olga Lima Tavares
authors.initials: OL
authors.lastname: Machado
mesh_terms: D055516:2S Albumins, Plant / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D052179:Antigens, Plant / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D002367:Ricinus communis / Q000737:chemistry* / Q000378:metabolism; D001517:Coleoptera / Q000737:chemistry / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D019476:Insect Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D012639:Seeds / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D000516:alpha-Amylases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism
chemical_list: D055516:2S Albumins, Plant; D052179:Antigens, Plant; D004791:Enzyme Inhibitors; D019476:Insect Proteins; D000516:alpha-Amylases