Chromatography-Independent Fractionation and Newly Identified Molecular Features of the Adzuki Bean (Vigna angularis Willd.) β-vignin Protein

Abstract

Adzuki seed β-vignin, a vicilin-like globulin, has proven to exert various health-promoting biological activities, notably in cardiovascular health. A simple scalable enrichment procedure of this protein for further nutritional and functional studies is crucial. In this study, a simplified chromatography-independent protein fractionation procedure has been optimized and described. The electrophoretic analysis showed a high degree of homogeneity of β-vignin isolate. Furthermore, the molecular features of the purified protein were investigated. The adzuki bean β-vignin was found to have a native size of 146 kDa, and the molecular weight determined was consistent with a trimeric structure. These were identified in two main polypeptide chains (masses of 56–54 kDa) that are glycosylated polypeptides with metal binding capacity, and one minor polypeptide chain with a mass 37 kDa, wherein these features are absent. The in vitro analysis showed a high degree of digestibility of the protein (92%) and potential anti-inflammatory capacity. The results lay the basis not only for further investigation of the health-promoting properties of the adzuki bean β-vignin protein, but also for a possible application as nutraceutical molecule.

Soybean (Glycine max) INFOGEST Colonic Digests Attenuated Inflammatory Responses Based on Protein Profiles of Different Varieties

“…β-Conglycinin is the vicilin storage protein of soybean, and it was evaluated to have multiple health benefits including modulating lipid accumulation and reducing risk of obesity and nonalcoholic fatty liver disease as reviewed by [40]. Vicilin is also present in other legumes such as mung bean, cowpea, and adzuki bean with increasing interest in its potential health benefits [41][42][43]. One study [42] found that β-vignin, a vicilin-like protein from adzuki bean, was able to reduce the activation of IL-8 to basal level [42].…”

“…Vicilin is also present in other legumes such as mung bean, cowpea, and adzuki bean with increasing interest in its potential health benefits [41][42][43]. One study [42] found that β-vignin, a vicilin-like protein from adzuki bean, was able to reduce the activation of IL-8 to basal level [42]. Therefore, β-conglycinin from the SCD samples potentially contributed to anti-inflammation through the inhibition of the NF-κB signaling pathway and inhibition of inflammation-related enzymes as was shown in the correlations.…”

Nutritional Potential of Adzuki Bean Germplasm and Mining Nutri-Dense Accessions through Multivariate Analysis

“…Adzuki bean protein content is at par with other pulses like chickpea (21.5 g/100 g), green gram (22.5 g/100 g), black gram (21.9 g/100 g), and peas (20.4 g/100 g) [45]. Additionally, adzuki bean protein also possesses other known health-promoting properties, such as ACE inhibitory activity (a substance that narrows blood vessels) and anti-inflammatory properties [46,47]. Adzuki beans can be integrated with climate resilience, organic farming, multi-cropping, low carbon and water footprint, and sustainable food production systems.…”

Adzuki bean (Vigna angularis): Chemical compositions, physicochemical properties, health benefits, and food applications

“…The adzuki bean protein was predominated by vicilin‐like (7S) globulin (about 78%), whereas the legumin‐like (11S) globulin only accounts for nearly 12% (Meng & Ma, 2001). Adzuki bean β‐vignin, the 7S globulin with multiple health benefits, had high in vitro digestibility (91%) as measured by pepsin and pancreatin (Philadelpho et al., 2021). The protein efficiency ratio of adzuki bean protein was close to 3, which suggested its good nutritional value and digestibility (Ge, Sun, et al., 2021).…”

“…Adzuki bean extracts and isolates also show anti‐inflammatory effects in vitro and in vivo. Cellular studies indicated the anti‐inflammatory effects of the adzuki bean isolates, such as β‐vignin protein, saponins, and terpenoids, were suggested by the inhibition of interleukin (IL)−8 and nitric oxide production (Jiang et al., 2014; Philadelpho et al., 2021). In animal studies, red (Kim et al., 2019) and black (Yook et al., 2017) adzuki bean extracts inhibited the production of pro‐inflammatory transcription factors, such as tumor necrosis factor (TNF)‐α, IL‐1, and IL‐6, via the suppression of nuclear factor kappa light chain enhancer of activated B cells (NF‐κB).…”