The use of UniProtKB/BIOPEP for the analysis of oat globulin physicochemical parameters and bioactivity

The physico-chemical properties of oat proteins (globulins) were determined and an analysis was done whether products of in silico proteolysis contain mono- and multi-functional peptides with various biological activity. The MW(s), calculated by the ProtParam program, for precursors of 12S and 11S globulins and proteins without signal peptides were in the range of 50.78–61.86 kDa. The pH at which the solubility of the proteins under analysis was the lowest ranged from 7.29 to 9.44. A simulation of proteolysis with three enzymes (pepsin, trypsin, and chymotrypsin A) in the optimum conditions of the enzyme action can produce 6–8 bi-functional, 5–10 mono-functional biopeptides from oat globulins (12S, 11S globulins), and one tri-functional biopeptide (VY). The mono-functional biopeptides exhibited the activity of DPPIV inhibitors or ACE inhibitors, and the multi-functional biopeptides can exhibit the activity of inhibitors of both enzymes (DPPIV and ACE). Sensory peptides accounted for 43% of all the released mono- and multi-functional biopeptides.

ASSESSMENT OF THE HEMOAGLUTINANT AND DIGESTIVE ENZYME INHIBITORY ACTIVITY OF EXTRACTS OBTAINED FROM DIFFERENT PARTS OF ATEMOIA

ABSTRACT The benefits of various foods, such as fruits and vegetables, have been the focus of several studies aimed at improving welfare, health, and reducing the incidence of diseases. Therefore, the present paper objectified to investigate the presence of molecules of biotechnological and pharmacological interest in peel, seed, and pulp of Annona x atemoya Mabb. Aqueous extracts of the fruit parts were obtained with different buffers and assessed as to their protein and phenolic compounds content. The three parts of the fruit presented different proportions of these compounds when subject to different extraction conditions, with the highest concentrations of proteins being found in the seed and phenolic compounds in the peel of the studied fruit. Bioactive proteins (protease inhibitors and lectins) were detected through inhibitory tests for trypsin and chymotrypsin and hemagglutinating activity tests with human erythrocytes. A variation of 400 to 9600 inhibition units for the trypsin in the analyzed extracts, whereas for chymotrypsin a variation of 200 to 2500 in the inhibition units for the three fruit parts, considering the different extraction conditions were identified. The extracts obtained from the seeds and the peel presented titers higher than 0.9 hemagglutination units, suggesting that the by-products from the processing of A. x atemoya are potential sources of bioactive molecules.

Food for Thought: Enzyme Action

Nature makes use of the tools that I have been developing, and does so in the most extraordinary and subtle manner. After all, she has had about four billion years to come up with solutions to problems with which human chemists have striven seriously for only a century or so. Most of the reactions that go on in organisms—including you—are controlled by the proteins called ‘enzymes’ (a name derived from the Greek words for ‘in leaven’, as in yeast). Enzymes are biological catalysts (Reaction 11) that are extraordinarily specific and highly effective in their role. One of these complex molecules might serve as the merest foot soldier in the army of reactions going on inside you, with a role such as severing the bond between two specific groups of atoms in a target molecule. Because their function may be highly specific, enzyme molecules need to be large: they have to recognize the molecule they act on, act on it, then release it so that they can act again. Thus, they have to have several functions built into them. As you will see, enzymes are the ultimate in functional blindness: they feel around in their surroundings in order to identify their substrate, the species they can act on. Life is ultimately blind chemical progress guided by touch. I am going to introduce you to one particular group of enzymes, the ‘proteases’, and focus on one example from this group, namely chymotrypsin. A protease is a traitor to its kind: it is a protein that breaks down other proteins. It plays a role in digestion, of course, but its range is much wider. One protease enables a lucky sperm to eat through the cell wall of an egg and ensure its at least temporary immortality. Another facilitates the clotting of blood to terminate possibly fatal bleeding. Chymotrypsin itself is an enzyme that is secreted from the pancreas into the intestine, and makes an essential contribution to the process of digestion. Its name is derived slightly circuitously from the Greek words for animal fluid, a bodily ‘humour’, and rubbing, as it was obtained as a fluid by rubbing the pancreas.