Proteomics is the complete evaluation of the function and structure of proteins to understand an organism’s nature. Mass spectrometry is an essential tool that is used for profiling proteins in the cell. However, biomarker discovery remains the major challenge of proteomics because of their complexity and dynamicity. Therefore, combining the proteomics approach with genomics and bioinformatics will provide an understanding of the information of biological systems and their disease alteration.
The study of proteomics has many applications in different fields such as medicine, oncology, food microbiology, and agriculture. Proteomics has three main types: expression proteomics, functional proteomics, and structural proteomics.
One use is as biomarkers for diagnosing cancer and other conditions and illnesses. In this 2016 study Italian researchers found 181 biomarkers in hempseed, increasing the grain’s value for medicine as well as food.
Proteomic characterization of hempseed (Cannabis Sativa L.)
“Many factors favor the reintroduction of the cultivation of this plant: it is a multipurpose crop with numerous applications in different industrial sectors [7] and it is particularly sustainable, since it rarely requires irrigation and the fast growth reduces the use of herbicides.
The great interest for hempseed depends on its nutritional content (whole seed): 35.5% oil, 24.8% protein, 20-30% carbohydrates, 27.6% total fiber (5.4% digestible and 22.2% non-digestible fiber) and 5.6% ash [8]. Moreover, the concentration of the main antinutritional factors, such as phytic acid, condensed tannins, and trypsin inhibitors, is low [9]. Currently, the main industrial interest is for the oil that has numerous applications either in food or body care products, being rich in polyunsaturated fatty acids [9].
In the meanwhile, however, there is an increasing attention for hempseed protein owing to its digestibility [10], satisfactory essential amino acid composition [10], and techno-functional properties [11-13]. Moreover, hempseed protein has also potential applications in nutraceutics and functional foods, since the treatment with suitable enzymes permits to produce hydrolyzed proteins providing useful health benefits, as hypotensive agents [14-16] and antioxidants [14, 17, 18].”
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“Literature indicates that a major protein in hempseed is edestin, a storage protein [12]. Edestin, a hexameric 11S protein, is easily digested and contains significant amounts of all essential amino acids [8], especially sulfur amino acids [19] and arginine [12].
Hempseed proteome has been investigated only once in the Korean cultivar Cheungsam [20]: the use of conventional techniques, such as 2-dimensional electrophoresis, mass spectrometry, and search in the nr-NCBI protein database permitted to identify 168 unique protein spots [20]. However, only one was assigned to C. sativa, whereas most of them were assigned to Medicago sativa, Oryza sativa or other plants. The current improved availability of genome information about C. sativa as well as the increasing interest for this seed prompted us to investigate again hempseed proteome. This research was performed on the seeds of the French cultivar Futura.
In order to get as much as possible a comprehensive information, combinatorial peptide ligand libraries (CPLLs) were used for protein equalization [21, 22]. This is a powerful and highly sensitive technique allowing access to low- and very-low-abundance proteins, which enlarges very much the possibility of protein identification. This technique has been applied, for example, to the analysis of the proteomes of donkey milk [23] and champagne [24], or to the detection of corn allergens [25].
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“Biological significance: Hempseed is an underexploited non-legume protein-rich seed. Although its protein is well-known for its digestibility, essential amino acid composition, and useful technofunctional properties, a comprehensive proteome characterization is still lacking. The objective of this work was to fill this knowledge gap and provide information useful for a better exploitation of this seed in different food products.”
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“Abstract.
This paper presents an investigation on hempseed proteome. The experimental approach, based on combinatorial peptide ligand libraries (CPLLs), SDS-PAGE separation, nLC-ESI-MS/MS identification, and database search, permitted identifying in total 181 expressed proteins. This very large number of identifications was achieved by searching in two databases: Cannabis sativa L. (56 gene products identified) and Arabidopsis thaliana (125 gene products identified). By performing a protein-protein association network analysis using the STRING software, it was possible to build the first interactomic map of all detected proteins, characterized by 137 nodes and 410 interactions. Finally, a Gene Ontology analysis of the identified species permitted to classify their molecular functions: the great majority is involved in the seed metabolic processes (41%), responses to stimulus (8%), and biological process (7%).
Biological significance: Hempseed is an underexploited non-legume protein-rich seed. Although its protein is known for its digestibility, essential amino acid composition, and useful techno-functional properties, a comprehensive proteome characterization is still lacking. The objective of this work was to fill this knowledge gap and provide information useful for a better exploitation of this seed.”
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“4.4. Conclusion
Taking advantage of high-throughput technologies, this work has provided very innovative information on hempseed proteome, since it was possible to identify in total 181 unique gene products, 56 specific protein species identified through the C. sativa database search and 125 protein species through the A. thaliana database search. This represents a main improvement in respect to available literature were all assignments were based on other plant databases [20]. In addition, it provides the first interactomic map of C. sativa, composed by a complex grid formed by 137 nodes connected via 410 interactions, useful to explore proteins relations and to understand the C. sativa biological pathways. The relevance of this work is underlined by the increasing interest for including hempseed ingredients in regular foods and, potentially, in functional ones. In fact, recent investigations have shown that peptides deriving from the gastrointestinal simulated digestion of hempseed proteins are characterized by useful antioxidant [16] and antihypertensive properties [15].”
Read more at: https://pubmed.ncbi.nlm.nih.gov/27265319/