246 research outputs found
Technological approaches to the extraction and purification by ultrafiltration techniques of target protein molecules from animal tissues: a review
Effective isolation and purification of protein is a great challenge nowadays. The key aspect is protein stability and solubility, which primarily depend on protein structure and its amino acid sequence. Manipulations with pH and ionic strength are the first at tempts to increase protein stability and solubility. Different additives that are allowed or prohibited in the food industry are applied for overcoming protein aggregation. Sugars, polyhydric alcohols and amino acids are the most attractive among them. Trehalose, glycerol, arginine, glycine and proline demonstrated outstanding properties that make them perspective for application during iso lation and purification of proteins singly or in combination with each other or othercompounds. However, the algorithm of effective isolation and purification of protein could be significantly varied depending on its structure. Effective isolation and purification of protein is a great challenge nowadays. The key aspect is protein stability and solubility, which primarily depend on protein structure and its amino acid sequence. Manipulations with pH and ionic strength are the first at tempts to increase protein stability and solubility. Different additives that are allowed or prohibited in the food industry are applied for overcoming protein aggregation. Sugars, polyhydric alcohols and amino acids are the most attractive among them. Trehalose, glycerol, arginine, glycine and proline demonstrated outstanding properties that make them perspective for application during iso lation and purification of proteins singly or in combination with each other or othercompounds. However, the algorithm of effective isolation and purification of protein could be significantly varied depending on its structure
Study of the functional product’s protein compounds digestion features
The aim of the study was to investigate the transformation of meat product’s proteins from pig hearts and aortas during enzymatic hydrolysis in an in vitro model of the gastrointestinal tract. The model consisted of three phases simulating digestion processes: “oral cavity” phase (a-amylase, pH 7.0; 2 min), “stomach” phase (pork pepsin, pH 3.0; 120 min), “intestine” phase (pork pancreatin, pH 7.0; 130 min). The product was sequentially subjected to hydrolysis, at the end of each phase, samples were taken to determine the protein concentration (biuret method) and visualize the protein fractions (one-dimensional electrophoresis). A significant increase in protein concentration at the “stomach” phase was revealed by 3.2 times, and the absolute content by 4.6 times. At the “intestine” phase, a decrease in the number of peptide complexes with copper ions by 1.8 times, the absolute protein content by 8.5% was re‑ vealed. The noted tendency was confirmed by electrophoretic studies — at the stage, simulating digestion in the stomach, the prod‑ ucts of meat product’s proteins hydrolysis were visualized; at the “intestine” phase, a low expression of protein fractions in the range of more than 10 kDa is shown. The maximum hydrolysis of protein compounds at the “stomach” phase to poly- and oligopeptides was confirmed, continuing at the “intestine” stage with the accumulation of free amino acids. This methodology makes it possible to visualize the products of hydrolysis of proteins in a meat product at all stages of the model and to monitor changes in protein concentration in the system
Technological approaches to the extraction and purification by ultrafiltration techniques of target protein molecules from animal tissues: a review
Effective isolation and purification of protein is a great challenge nowadays. The key aspect is protein stability and solubility, which primarily depend on protein structure and its amino acid sequence. Manipulations with pH and ionic strength are the first at tempts to increase protein stability and solubility. Different additives that are allowed or prohibited in the food industry are applied for overcoming protein aggregation. Sugars, polyhydric alcohols and amino acids are the most attractive among them. Trehalose, glycerol, arginine, glycine and proline demonstrated outstanding properties that make them perspective for application during iso lation and purification of proteins singly or in combination with each other or othercompounds. However, the algorithm of effective isolation and purification of protein could be significantly varied depending on its structure
Coisotropic Branes, Noncommutativity, and the Mirror Correspondence
We study coisotropic A-branes in the sigma model on a four-torus by
explicitly constructing examples. We find that morphisms between coisotropic
branes can be equated with a fundamental representation of the noncommutatively
deformed algebra of functions on the intersection. The noncommutativity
parameter is expressed in terms of the bundles on the branes. We conjecture
these findings hold in general. To check mirror symmetry, we verify that the
dimensions of morphism spaces are equal to the corresponding dimensions of
morphisms between mirror objects.Comment: 13 page
Matrix Factorizations and Homological Mirror Symmetry on the Torus
We consider matrix factorizations and homological mirror symmetry on the
torus T^2 using a Landau-Ginzburg description. We identify the basic matrix
factorizations of the Landau-Ginzburg superpotential and compute the full
spectrum, taking into account the explicit dependence on bulk and boundary
moduli. We verify homological mirror symmetry by comparing three-point
functions in the A-model and the B-model.Comment: 41 pages, 9 figures, v2: reference added, minor corrections and
clarifications, version published in JHE
Biotechnological techniques for intensification of protein extraction from the porcine pancreas
Processing of secondary products after slaughter of farm animals is in demand. The pancreas is a rich source of bioactive protein substances, effective extraction of which is a serious problem today due to their aggregation. The aim of the work was to assess the extractivity of protein substances of the porcine pancreas using sodium chloride, trehalose, arginine, and combination of glycine and proline. The protein concentration was determined in the obtained extracts by the biuret reaction and their protein composition was assessed by densitometry of two-dimensional electropherograms using software ImageMaster™ 2D Platinum powered by Melanie 8.0. The results showed a positive effect of anti-aggregation agents on the release of protein substances into a solution. The highest protein concentration (33.36±0.64 g/l) was observed when adding 1М L-arginine; however, it was conditioned mainly by an increase in the content of three major protein fractions rather than by diversity of the protein composition. In general, the use of 0.9% NaCl as an extractive agent was quite effective, but selectivity to certain protein groups was observed for anti-aggregation agents such as sodium chloride, trehalose, arginine, glycine and proline, as well as their combination. The obtained results are important for intensifying extraction of protein substances including target ones with the subsequent application in different fields
Mirror duality and noncommutative tori
In this paper, we study a mirror duality on a generalized complex torus and a
noncommutative complex torus. First, we derive a symplectic version of Riemann
condition using mirror duality on ordinary complex tori. Based on this we will
find a mirror correspondence on generalized complex tori and generalize the
mirror duality on complex tori to the case of noncommutative complex tori.Comment: 22pages, no figure
A Point's Point of View of Stringy Geometry
The notion of a "point" is essential to describe the topology of spacetime.
Despite this, a point probably does not play a particularly distinguished role
in any intrinsic formulation of string theory. We discuss one way to try to
determine the notion of a point from a worldsheet point of view. The derived
category description of D-branes is the key tool. The case of a flop is
analyzed and Pi-stability in this context is tied in to some ideas of
Bridgeland. Monodromy associated to the flop is also computed via Pi-stability
and shown to be consistent with previous conjectures.Comment: 15 pages, 3 figures, ref adde
Mixed-symmetry massive fields in AdS(5)
Free mixed-symmetry arbitrary spin massive bosonic and fermionic fields
propagating in AdS(5) are investigated. Using the light-cone formulation of
relativistic dynamics we study bosonic and fermionic fields on an equal
footing. Light-cone gauge actions for such fields are constructed. Various
limits of the actions are discussed.Comment: v3: 24 pages, LaTeX-2e; typos corrected, footnote 7 and 2 references
added, published in Class. Quantum Gra
Determinantal Characterization of Canonical Curves and Combinatorial Theta Identities
We characterize genus g canonical curves by the vanishing of combinatorial
products of g+1 determinants of Brill-Noether matrices. This also implies the
characterization of canonical curves in terms of (g-2)(g-3)/2 theta identities.
A remarkable mechanism, based on a basis of H^0(K_C) expressed in terms of
Szego kernels, reduces such identities to a simple rank condition for matrices
whose entries are logarithmic derivatives of theta functions. Such a basis,
together with the Fay trisecant identity, also leads to the solution of the
question of expressing the determinant of Brill-Noether matrices in terms of
theta functions, without using the problematic Klein-Fay section sigma.Comment: 35 pages. New results, presentation improved, clarifications added.
Accepted for publication in Math. An
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