title: A Kunitz proteinase inhibitor from corms of Xanthosoma blandum with bactericidal activity.
abstract: Bacterial infections directly affect the world's population, and this situation has been aggravated by indiscriminate use of antimicrobial agents, which can generate resistant microorganisms. In this report, an initial screening of proteins with antibacterial activity from corms of 15 species of the Xanthosoma genus was conducted. Since Xanthosoma blandum corms showed enhanced activity toward bacteria, a novel protein with bactericidal activity was isolated from this particular species. Edman degradation was used for protein N-termini determination; the primary structure showed similarities with Kunitz inhibitors, and this protein was named Xb-KTI. This protein was further challenged against serine proteinases from different sources, showing clear inhibitory activities. Otherwise, no hemolytic activity was observed for Xb-KTI. The results demonstrate the biotechnological potential of Xb-KTI, the first proteinase inhibitor with antimicrobial activity described in the Xanthosoma genus.
authors.affiliation: Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, Brazil.
authors.forename: Thaís B
authors.initials: TB
authors.lastname: Lima
authors.forename: Osmar N
authors.initials: ON
authors.lastname: Silva
authors.forename: Ludovico
authors.initials: L
authors.lastname: Migliolo
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Souza-Filho
authors.forename: Eduardo G
authors.initials: EG
authors.lastname: Gonçalves
authors.forename: Ilka M
authors.initials: IM
authors.lastname: Vasconcelos
authors.forename: José T A
authors.initials: JT
authors.lastname: Oliveira
authors.forename: André C
authors.initials: AC
authors.lastname: Amaral
authors.forename: Octávio L
authors.initials: OL
authors.lastname: Franco
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D012697:Serine Endopeptidases / Q000378:metabolism; D031063:Xanthosoma / Q000737:chemistry* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; C053865:Kunitz-type protease inhibitor, plant; D010455:Peptides; D010940:Plant Proteins; D012697:Serine Endopeptidases