On seed proteins Part 11. Purification, Chemical Composition, and Some Physico‐chemical Properties of the 11 S Globulin (Helianthinin) in Sunflower Seed

Abstract

An improved procedure for the isolation and purification of the 11 S globulin from sunflower seeds (helianthinin) is described, including a combined purification by gel chromatography and ionexchange chromatoThe protein has a sedimentation constant of szo, = 12.8 x lo-'' s, a STOKES radius of 57 A and a diffusion constant of 3.76 x lo-' cm2 s-' (the last two derived from gel chromatographic analysis). Hence it follows a molecular weight of M, = 305000. The isoelectric point determined by isoelectric focusing lies at pH 4.7.High contents of glutamic (26%) and aspartic (14%) acid and arginine (9.7 %) as well as a low content of sulphur containing amino acids are characteristic for the amino acid composition. 59 % of the acidic amino acids are present in an amidated form. The globulin contains 12 disulphide bridges per molecule. graphy.Helianthinin is the main storage protein in sunflower seed [l]. It represents a typical 11 S globulin with a molecular weight near 300000, dissociation properties depending on pH and ionic strength, a low content of a-helix, a relatively high amount of p-conformation, and a high content of arginine, glutamic and aspartic acid (2-51. In the present paper an improved purification for the globulin combining gel filtration and ion-exchange chromatography, the corrected amino acid composition, the content of amide-nitrogen and SS/SHgroups, and some physico-chemical properties of the globulin are described. Material and Methods Protein isolationGround dehulled sunflower seeds were defatted with diethyl ether and extracted with a 5% solution of sodium chloride in a cold room. The protein was precipitated with cold water and twice chromatographed on Sephadex G-200 as described in a previous paper [6].

New natural injection-moldable composite material from sunflower oil cake

“…The isolated protein corpuscles ( Figure 2C) had a well-defined spherical shape and a diameter in the range between 2 and 6 µm while other plastids were agglomerated in a non-well-defined-shape aggregate and had elongated forms ( Figure 2D). If the first ones can be identified as spare globulin, the others could be globulins too, but bound to complexes constituted by some denatured albumins and some phenolic compounds formed during the extraction of oil (Shahidi and Nazck, 1992), corresponding then to the definition given by certain authors for sunflower glutelins (Gueyasuddin et al, 1970;Schwenke et al, 1979).…”

Modification of the oligomeric structure of 11 S globulin from sunflower (Helianthus annuus L.) and rape (Brassica napus L.) seeds by succinylation

“…After extraction with 5 % sodium chloride, the 1 IS globulin was purified by gel and ionexchange chromatography as described previously [2].…”

Modification of structural and functional properties of sunflower 11S globulin hydrolysates

“…protease inhibitors, cyanogens, glucosinolates, hence they are considered to be a valuable alternative as food ingredients (Gonzalez-Perez & Vereijken 2007). The sunflower proteins consist of four fractions (1.7, 7.8, 11.9, and 18.1 S) designated by sedimentation coefficients (Schwenke et al 1979), of which sunflower 11S globulin is the major protein fraction, ranging from 40% to 90% (Gonzalez-Perez & Vereijken 2007). The properties of sunflower 11S globulin are important.…”