Comparative studies on seed protein characteristics in eight lines of two Gossypium species

Abstract

Background: In order to achieve the targets aiming at the improvement of protein quality, knowledge regarding seed protein fractions and polypeptides constituting them in different crops is essential. Besides having high nutritional value as animal feed and human food, the protein isolates from cottonseed meal have also been proven promising as industrial raw materials for a number of applications. As far as Indian work on the characterization of cotton seed proteins is concerned, relatively meagre reports are available. Keeping in mind the importance of cotton seed proteins, lines belonging to Gossypium arboreum L. (Indian cotton) and G. hirsutum L. (American cotton) which are grown in all the major cotton growing states in India were selected for analysing their seed protein characteristics. Results: Whereas G. arboreum (A-genome) lines revealed a lower range of seed protein content i.e. 19.5~24.3%, an upper range (21.8~29.5%) could be observed in lines of G. hirsutum (AD-genome). Globulins represented dominating fraction in both species followed by albumins, glutelins and prolamins. A significant positive correlation between albumins/globulins and seed protein content in G. arboreum /G. hirsutum, respectively, was observed. Intraspecific electrophoretic variation in seed protein extracts was observed in the region of molecular weight 22 kDa-27 kDa in lines of both the species; however some lines with A-genome showed similarity in banding pattern with AD-genome. Four polypeptides with disulphide-linkages were also reported for the first time. Albumins were observed to reveal more variations in their electrophoretic pattern between the lines of two species followed by globulins. Conclusion: On the basis of present and previous studies, screening the lines with low or high protein content will lead the selection of lines with superior polypeptide fraction important for nutritional and industrial purposes. On comparing the composition and behaviour of four 2-S linked polypeptides with other plant groups, these were suggested to be legumin-like in nature. The similarity in banding patterns between the lines of A-genome and AD-genome species marked towards the close evolutionary relationship between these two. Albumin fractions on the basis of our results could be taken for cultivar differentiation in cotton crop.

Grass pea (Lathyrus sativus L.) protein yield and functionality as affected by extraction method: Alkaline, ultrasound‐assisted, and ultrasound pretreatment extraction

“…Singh and Kaur (2019) reported that polypeptides in the range of molecular weight of 12−120 kDa and 11.5−122 kDa correspond to albumin and globulin (salt‐soluble) fractions, respectively. SDS‐PAGE pattern of GPI in the research of Feyzi et al (2018) showed higher molecular weight peptides in freeze‐dried samples (range: 20−140 kDa) compared with vacuum oven dried.…”

“…Also, there were no subunits of ~27 and ~32 kDa after freeze-drying, while subunits of around 32 kDa might be attributed to phytohemagglutinin, a common antinutritional agent in beans. Singh and Kaur (2019) reported that polypeptides in the range of molecular weight of 12−120 kDa and 11.5−122 kDa correspond to albumin and globulin (saltsoluble) fractions, respectively. SDS-PAGE pattern of GPI in the research of Feyzi et al (2018) showed higher molecular weight peptides in freeze-dried samples (range: 20−140 kDa) compared with vacuum oven dried.…”

Cottonseed: A sustainable contributor to global protein requirements

“…In another study, out of 4 protein fractions, globulins reached a maximum (33-63.7%), followed by albumins (20.8-32.2%), glutelins (9.1-28%), and prolamins at the lowest concentration (Singh & Kaur, 2019). The molecular weights of polypeptides in cottonseed protein from Gossypium arboreum and Gossypium hirsutum lines were found to be in the range of 10-122 kDa (Singh & Kaur, 2019). The molecular weight of the alkali-soluble protein fraction varied from 10-54 kDa in both species.…”

“…These protein subunits include both salt-(globulins 5S: 24 and 22 kDa) and water-soluble fractions (albumins; albumin 2S: 20, 15 and 14 kDa) (Sun et al, 2012). In another study, out of 4 protein fractions, globulins reached a maximum (33-63.7%), followed by albumins (20.8-32.2%), glutelins (9.1-28%), and prolamins at the lowest concentration (Singh & Kaur, 2019). The molecular weights of polypeptides in cottonseed protein from Gossypium arboreum and Gossypium hirsutum lines were found to be in the range of 10-122 kDa (Singh & Kaur, 2019).…”

A Review of Cottonseed Protein Chemistry and Non-Food Applications

“…The molecular weight changes with maturation [49]. Recently, Singh et al [50] applied one-and two-dimensional gel electrophoresis to explore the cottonseed protein characteristics. They compared the relative distribution of four protein fractions (i.e., albumins, globulins, prolamins and glutelins) of cottonseed in eight lines of two Gossypium species and found that globulins represented the dominating fraction in both species followed by albumins, glutelins and prolamins.…”