Analysis of the size of protein molecules obtained from a legume plant material

Obesity is a problem in the present-day world. Excess weight leads to the cardiovascular diseases, type 2 diabetes mellitus. As an alternative to a low glycemic index diet, there are foods that slow down the absorption of carbohydrates by inhibiting the enzymes responsible for their fixation. These products include α-amylase and glucosidase inhibitors. Protein compounds with an inhibitory activity are contained in large quantities in assorted of beans. Depending on the method of extraction, concentration, isolation, many inhibitor preparations can lose its activity during the use. Therefore, production of purified inhibitors with high biological activity is an urgent task. The modern methods for extracting substances from plant materials, for example, fractionation, supercritical extraction, lead to an increase in the activity of bioactive substances. In this regard, the purpose of the work is to study the size of the particles of protein substances extracted from the seeds of red beans using the light-scattering method and to determine their biological activity. Bovine serum albumin was used as a model object. When studying the particle size, it was shown that detection at 15° reveals only large particles, and an angle of 90° allows simultaneously small (6-20 nm) and large (up to 6000 nm) protein fractions to be fixed. In phosphate buffer, serum albumin particles form agglomerates (~ 6000 nm), and in water, particles can be present in monomeric and dimeric forms (~ 1000 nm). Protein substances obtained by extraction from red beans into a buffer solution of pH 8 are enlarged aggregates. The size of protein particles decreases from 620 nm to 380 nm when the ultrasonic irradiation was used. Studies of the biological activity of protein substances in relation to pancreatic amylase have shown that the activity of the enzyme decreases from 28 U/g to 15 U/g and to 5 U/g when using protein substances obtained by maceration and in a cavitation field, respectively.