title: Bacillus subtilis 168 levansucrase (SacB) activity affects average levan molecular weight.
abstract: Levan is a fructan polymer that offers a variety of applications in the chemical, health, cosmetic and food industries. Most of the levan applications depend on levan molecular weight, which in turn depends on the source of the synthesizing enzyme and/or on reaction conditions. Here we demonstrate that in the particular case of levansucrase from Bacillus subtilis 168, enzyme concentration is also a factor defining the molecular weight levan distribution. While a bimodal distribution has been reported at the usual enzyme concentrations (1 U/ml equivalent to 0.1 μM levansucrase) we found that a low molecular weight normal distribution is solely obtained al high enzyme concentrations (>5 U/ml equivalent to 0.5 μM levansucrase) while a high normal molecular weight distribution is synthesized at low enzyme doses (0.1 U/ml equivalent to 0.01 μM of levansucrase).
authors.affiliation: Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, CP 62240 Cuernavaca, Morelos, Mexico. Electronic address: jrpd@ibt.unam.mx.
authors.forename: Jaime R
authors.initials: JR
authors.lastname: Porras-Domínguez
authors.affiliation: Centro de Investigación, DACS-Universidad Juárez Autónoma de Tabasco, Av. Gregorio Méndez no. 2838-A. Col. Tamulte, CP 86150 Villahermosa, Centro, Tabasco, Mexico. Electronic address: angela.avila@ujat.mx.
authors.forename: Ángela
authors.initials: Á
authors.lastname: Ávila-Fernández
authors.affiliation: Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, CP 62240 Cuernavaca, Morelos, Mexico; Centro de Investigación, DACS-Universidad Juárez Autónoma de Tabasco, Av. Gregorio Méndez no. 2838-A. Col. Tamulte, CP 86150 Villahermosa, Centro, Tabasco, Mexico.
authors.forename: Afonso
authors.initials: A
authors.lastname: Miranda-Molina
authors.affiliation: Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, CP 62240 Cuernavaca, Morelos, Mexico. Electronic address: maelena@ibt.unam.mx.
authors.forename: María Elena
authors.initials: ME
authors.lastname: Rodríguez-Alegría
authors.affiliation: Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, CP 62240 Cuernavaca, Morelos, Mexico. Electronic address: agustin@ibt.unam.mx.
authors.forename: Agustín López
authors.initials: AL
authors.lastname: Munguía
mesh_terms: D001412:Bacillus subtilis / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D005630:Fructans / Q000737:chemistry* / Q000378:metabolism*; D006602:Hexosyltransferases / Q000032:analysis / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D008970:Molecular Weight; D013395:Sucrose / Q000378:metabolism; D013696:Temperature
chemical_list: D005630:Fructans; D013395:Sucrose; C072599:levan; D006602:Hexosyltransferases; C021513:levansucrase
keywords: Fructan; Fructosyltransferase; Levan; Levansucrase; SacB; Transferase