Papers by Ana Cristina Ribeiro
Frontiers in Nutrition
There is a strong demand for plant-based milk substitutes, often low in protein content (<1.5%... more There is a strong demand for plant-based milk substitutes, often low in protein content (<1.5% w/v). Protein-rich pulse seeds and the right processing technologies make it possible to make relevant choices. The major objective of this study was to assess the impact of processing on the nutritional characteristics of beverages with a high impact on health, in particular on digestibility and specific bioactivities. The results suggest that pulse beverages are as high in protein content (3.24% w/v for chickpea and 4.05% w/v for lupin) as cow’s milk. The anti-nutrient level characteristics of pulses have been considerably reduced by strategic processing. However, when present in small quantities, some of these anti-nutritional factors may have health benefits. Controlling processing conditions play a crucial role in this fine balance as a tool to take advantage of their health benefits. There is evidence of protein hydrolysis by in vitro digestion and limited bioaccessibility of mine...
Studies in Natural Products Chemistry, 2018
Abstract Lectins are proteins that possess at least one noncatalytic domain that allows them to s... more Abstract Lectins are proteins that possess at least one noncatalytic domain that allows them to selectively recognize and reversibly bind specifically free sugars (monosaccharides) or oligosaccharides, present in the cell without altering the structure of carbohydrate which make possible their use as decoders of cellular carbohydrates. They have a largest distribution in nature in all kingdoms of life with a higher distribution in plants and also in animals and microorganisms. The plant lectins represent a unique group of proteins with potent biological activity, where legumes lectins represent the largest thoroughly studied family. Based on their mechanism of action, the plant lectins can exert action in diverse biological process as plant protection and in medicine as lectin-based delivery systems, biomedical research, as diagnostic and in disease treatment. In animal cells lectins can have action in various of biological process included the cellular adhesion, invasion, metastasis inhibition, action on angiogenesis and in cellular death by autophagy, necrose, and or apoptosis. The best-known legume lectins are phytohemagglutinin from red kidney beans ( Phaseolus vulgaris L.), soybean agglutinin from Glycine max , concanavalin A from jack bean ( Canavalia ensiformis ), peanut lectin from Arachis hypogaea , and pea lectin from Pisum sativum . Others important plant lectins with recognized antitumor activity (where ConA is included) are Ulex europaeus agglutinin, Viscum album coloratum agglutinin, mistletoe lectin, and Viscum album agglutinin from Viscum album L. and Galanthus nivalis agglutinin, among others. This review aims to give the state of art of lectins as potential candidates for the development of more efficient anticancer or cancer preventive drugs.
Food Science & Nutrition, 2021
International Journal of Molecular Sciences, 2019
Experiments conducted in vitro and in vivo, as well as some preclinical trials for cancer therape... more Experiments conducted in vitro and in vivo, as well as some preclinical trials for cancer therapeutics, support the antineoplastic properties of lectins. A screening of antitumoral activity on HT29 colon cancer cells, based on polypeptide characterization and specific lectin binding to HT29 cells membrane receptors, was performed in order to assess the bioactivities present in four Mediterranean plant species: Juniperus oxycedrus subsp. oxycedrus, Juniperus oxycedrus subsp. badia, Arbutus unedo and Corema album. Total leaf proteins from each species were evaluated with respect to cell viability and inhibitory activities on HT29 cells (cell migration, matrix metalloproteinase –MMP proteolytic activities). A discussion is presented on a possible mechanism justifying the specific binding of lectins to HT29 cell receptors. All species revealed the presence of proteins with affinity to HT29 cell glycosylated receptors, possibly explaining the differential antitumor activity exhibited by ...
Galactose is an energy-providing nutrient and also a necessary basic substrate for the biosynthes... more Galactose is an energy-providing nutrient and also a necessary basic substrate for the biosynthesis of many molecules in body, where it forms part of glycolipids and glycoproteins in several tissues. Galactose is found in dairy products, sugar beets, and others gums and mucilage and also in some meats, legumes and fruits, but in lesser amount. It is a monosaccharide which when combined with glucose, through a dehydration process, results in lactose, the milk sugar. In galactose metabolism, the liver plays an essential role. Carbohydrates derived from the diet as disaccharides or polysaccharides are broken down into simpler monosaccharides, which reach the liver via the portal blood system. The primary sugars in newborns and infants come from breakdown of disaccharide lactose in milk; lactose is broken down to glucose and galactose and when it reaches the hepatocytes, galactose is converted to glucose by a series of enzymatic reactions. Galactosemia is a relatively rare inherited enz...
Molecules, 2014
Legume lectins comprise a structurally related, Ca/Mn-dependent, widespread, abundant and well ch... more Legume lectins comprise a structurally related, Ca/Mn-dependent, widespread, abundant and well characterized lectin family when compared to the large number of lectins from other sources described in the literature. Strangely enough, no specific function has been assigned to them aside from a possible role in storage and/or defense. Using a recent and fine-tuned methodology capable of specific lectin identification, β-conglutin, Vicia faba vicilin and β-lathyrin, the vicilin storage globulins from Lupinus albus, V. faba and Lathyrus sativus, respectively, were shown to be capable of affinity binding to thoroughly washed erythrocyte membranes and of specific elution with appropriate sugars. Based on this evidence and on sparse data published in the literature, a second family of legume lectins is proposed: the 7S family of storage proteins from leguminous seeds, or family II of legume lectins. These lectins are also structurally related, widespread and well characterized. In addition, they self-aggregate in a Ca/Mg, electrostatic dependent manner and are even more abundant than the family I of legume lectins. Using the same evidence, reserve and defense roles may be attributed to family II of legume lectins.
Journal of Agricultural and Food Chemistry, 2004
The proteins from Vicia sativa L. (common vetch) seeds were investigated. Protein comprises ∼11.4... more The proteins from Vicia sativa L. (common vetch) seeds were investigated. Protein comprises ∼11.4% of the seed fresh weight, >50.8% of which is composed by globulins and 43.6% by albumins. The globulins may be fractionated into two main components, which were named R-vicinin (comprising 73% of the total globulin fraction, and hence >37% of the total seed protein) and-vicinin. Two minor globulin components are also present, γ-vicinin and δ-vicinin. R-Vicinin, the legumin-like globulin, with a sedimentation coefficient of 10.6 S, is a nonglycosylated, disulfide-bond-containing globulin, composed of a group of subunits with molecular masses ranging from 50 to 78 kDa. Upon reduction, each of these subunits releases a heavy polypeptide chain (34-66 kDa) and a light polypeptide chain (21-23 kDa).-Vicinin, the vicilin-like globulin, with a sedimentation coefficient of 7.7 S, is a nonglycosylated globulin that contains no disulfide bonds and consists of two major polypeptides with molecular masses of 58 and 66 kDa. γ-Vicinin is a minor, glycosylated, disulfide-bond-containing globulin. In the reduced form, it comprises six polypeptide chains with molecular masses of 12, 19, 21, 22, 23, and 31 kDa. Finally, δ-vicinin is a minor, highly glycosylated globulin that exhibits hemagglutinating activity. It is composed of a major 47 kDa polypeptide and two minor (33 and 38 kDa) polypeptides. N-terminal sequencing of the δ-vicinin 47 kDa polypeptide revealed no homology to any other known storage protein.
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Papers by Ana Cristina Ribeiro