title: Purification and characterization of recombinant supersweet protein thaumatin II from tomato fruit.
abstract: Thaumatin, a supersweet protein from the African plant katemfe (Thaumatococcus daniellii Benth.), is a promising zero-calorie sweetener for use in the food and pharmaceutical industries. Due to limited natural sources of thaumatin, its production using transgenic plants is an advantageous alternative. We report a simple protocol for purification of recombinant thaumatin II from transgenic tomato. Thaumatin was extracted from ripe tomato fruit in a low-salt buffer and purified on an SP-Sephacryl column. Recombinant thaumatin yield averaged 50 mg/kg fresh fruit. MALDI-MS analysis showed correct processing of thaumatin in tomato plants. The recombinant thaumatin was indistinguishable from the native protein in a taste test. The purified tomato-derived thaumatin had an intrinsic sweetness with a threshold value in taste tests of around 50 nM. These results demonstrate the potential of an expression system based on transgenic tomato plants for production of recombinant thaumatin for the food and pharmaceutical industries.
authors.affiliation: Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the RAS, Moscow Region, Pushchino, 142290, Russia. Electronic address: aleksey_firsov@mail.ru.
authors.forename: Aleksey
authors.initials: A
authors.lastname: Firsov
authors.affiliation: Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the RAS, Moscow Region, Pushchino, 142290, Russia.
authors.forename: Lyubov
authors.initials: L
authors.lastname: Shaloiko
authors.affiliation: Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the RAS, Moscow Region, Pushchino, 142290, Russia.
authors.forename: Oleg
authors.initials: O
authors.lastname: Kozlov
authors.affiliation: Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the RAS, Moscow Region, Pushchino, 142290, Russia.
authors.forename: Leonid
authors.initials: L
authors.lastname: Vinokurov
authors.affiliation: The Hebrew University of Jerusalem, Robert H. Smith Faculty of Agriculture, Food and Environment, POB 12, Rehovot, 76100, Israel.
authors.forename: Alexander
authors.initials: A
authors.lastname: Vainstein
authors.affiliation: Branch of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the RAS, Moscow Region, Pushchino, 142290, Russia.
authors.forename: Sergey
authors.initials: S
authors.lastname: Dolgov
mesh_terms: D015153:Blotting, Western; D002853:Chromatography, Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D005638:Fruit / Q000737:chemistry / Q000235:genetics; D018551:Solanum lycopersicum / Q000737:chemistry / Q000235:genetics*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D030821:Plants, Genetically Modified / Q000737:chemistry / Q000235:genetics*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013549:Sweetening Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D011994:Recombinant Proteins; D013549:Sweetening Agents; C003427:thaumatin protein, plant
keywords: Recombinant thaumatin II purification; Supersweet proteins; Thaumatin II; Transgenic tomato