title: Synthesis of Fructooligosaccharides by IslA4, a truncated inulosucrase from Leuconostoc citreum.
abstract: BACKGROUND
  IslA4 is a truncated single domain protein derived from the inulosucrase IslA, which is a multidomain fructosyltransferase produced by Leuconostoc citreum. IslA4 can synthesize high molecular weight inulin from sucrose, with a residual sucrose hydrolytic activity. IslA4 has been reported to retain the product specificity of the multidomain enzyme.
  
  
  RESULTS
  Screening experiments to evaluate the influence of the reactions conditions, especially the sucrose and enzyme concentrations, on IslA4 product specificity revealed that high sucrose concentrations shifted the specificity of the reaction towards fructooligosaccharides (FOS) synthesis, which almost eliminated inulin synthesis and led to a considerable reduction in sucrose hydrolysis. Reactions with low IslA4 activity and a high sucrose activity allowed for high levels of FOS synthesis, where 70% sucrose was used for transfer reactions, with 65% corresponding to transfructosylation for the synthesis of FOS.
  
  
  CONCLUSIONS
  Domain truncation together with the selection of the appropriate reaction conditions resulted in the synthesis of various FOS, which were produced as the main transferase products of inulosucrase (IslA4). These results therefore demonstrate that bacterial fructosyltransferase could be used for the synthesis of inulin-type FOS.
authors.affiliation: Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, C.P. 62210, México. arlen@ibt.unam.mx.
authors.forename: Arlen
authors.initials: A
authors.lastname: Peña-Cardeña
authors.affiliation: Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, C.P. 62210, México. maelena@ibt.unam.mx.
authors.forename: María Elena
authors.initials: ME
authors.lastname: Rodríguez-Alegría
authors.affiliation: Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, C.P. 62210, México. clarita@ibt.unam.mx.
authors.forename: Clarita
authors.initials: C
authors.lastname: Olvera
authors.affiliation: Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, C.P. 62210, México. agustin@ibt.unam.mx.
authors.forename: Agustín López
authors.initials: AL
authors.lastname: Munguía
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D006602:Hexosyltransferases / Q000737:chemistry / Q000378:metabolism*; D007444:Inulin / Q000096:biosynthesis; D007934:Leuconostoc / Q000201:enzymology*; D009844:Oligosaccharides / Q000096:biosynthesis*; D017434:Protein Structure, Tertiary; D013395:Sucrose / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D009844:Oligosaccharides; C116580:fructooligosaccharide; D013395:Sucrose; D007444:Inulin; D006602:Hexosyltransferases; C021451:inulosucrase