Physicochemical Properties of Native Adzuki Bean (Vigna angularis) 7S Globulin and the Molecular Cloning of Its cDNA Isoforms

Abstract

7S globulin (vicilin), the major seed storage protein in adzuki bean [Vigna angularis], was purified by ammonium sulfate fractionation, gel filtration column chromatography, and anion-exchange column chromatography that resulted in two fractions. On SDS-PAGE, both fractions gave two major and some minor bands, but there was a difference in the minor band compositions between the two fractions. Thermal stability, solubility, surface hydrophobicity, and emulsifying ability of these three samples were analyzed. Although there was no difference in solubility and emulsifying ability among the samples, thermal stability and surface hydrophobicity were different. These differences might be due to the differences in subunit compositions. cDNAs were cloned by reverse transcription-polymerase chain reaction (RT-PCR) using primers designed on the basis of the determined N-terminal sequences of the major bands. We obtained three isoforms of cDNAs, which had highest homology with the mung bean 8Salpha globulin (7S globulin), and then soybean beta-conglycinin (7S globulin) beta subunit among legume plants. Adzuki bean 7S globulin isoforms contain more methionine and tryptophan than mung bean 8Salpha globulin and soybean beta-conglycinin beta subunit. In addition, high mannose types of glycans were attached to two or one N-glycosylation sites of adzuki bean 7S globulins.

Chloroform-Assisted Phenol Extraction Improving Proteome Profiling of Maize Embryos through Selective Depletion of High-Abundance Storage Proteins

“…Obviously, maize vicilins consist of several major isoforms with similar sizes but different pIs (6.1–6.7), consistent with a previous study that vicilin from maize flour is composed of a string of six spots in 2-D gel, all of them allergenic [1]. Probably, this phenomenon resulted from three causes: (a) maize vicilin is encoded by a single but polymorphic Glb1 gene [7]–[8], which may contribute the subtle difference of the gene products (protein isoforms); (b) vicilin is a glycoprotein [17] and exists as a heterogeneous mixture after glycosylation; and (c) proteolytic modification occurred during vicilin synthesis also contributes the heterogeneity in vicilin species [18]–[19].…”

Crystal structure of a major seed storage protein, 11S proglobulin, from Amaranthus hypochondriacus: Insight into its physico-chemical properties

“…Some structural features cited to increase thermal stability of the 11S globulins are the high number of proline residues, reduced length of loops, and cavity size (Fukuda, Prak, Fujioka, Maruyama, & Utsumi, 2007;Maruyama et al, 2004). Proline residues in amaranth 11S proglobulin consist of 4.1% which is lower than soybean proA1aB1b, proA3B4, and procruciferin (6.1%, 7.3%, and 5.6%, respectively), but comparable to pumpkin 11S proglobulin and prolegumin (3.9% and 4.8%, respectively).…”

Comparative study of the functional properties of three legume seed isolates: adzuki, pea and soy bean

“…7S globulin is glycoprotein that consists of two types of subunits, α-and β 1 -subunits with molecular weight of 55 kDa, and 35 kDa, respectively (Chen et al 1984). Vicilin-like proteins undergo proteolytic modification or "nicking" and this processing creates a high degree of heterogeneity in the subunit population (Fukuda et al 2007). The second most abundant protein, legumin consists of two types of subunits, acidic and basic with a molecular mass of 40 and 20 kDa, respectively (Meng and Ma 2002a, b).…”

“…There are data reported on the foaming properties of adzuki protein concentrate (Chau et al 1997), solubility, surface M. B. Barac (*) : M. B. Pesic : S. P. Stanojevic : A. Z. Kostic hydrophobicity and thermal stability of purified 7S globulin of adzuki (Fukuda et al 2007(Fukuda et al , 2008 and thermal, emulsifying and gelling properties of globulin extracts of adzuki proteins (Meng et al 2002;Ma 2001, 2002a, b).…”