Proteins, combination with carbohydrates

NUCLEOPROTEINS AND NUCLEIC ACIDS. Nucleic adds are compounds in which phosphoric acid is combined with carbohydrates and with bases derived from purine and pyrimidine. Nucleoproteins are conjugated proteins consisting of a protein moiety and a nucleic acid. Originally, nucleoproteins were thought to occur only in the nuclei of cells, but it was later established that they are far more widely distributed, being found in cells of all types, animal and plant. They are found in the chromosomes, in the genes, in viruses, and bacteriophages. 

The stereochemical specificity of taste receptor proteins capable of combining with carbohydrate molecules and of translating the message into sweet sensation is investigated by Jakinovich using a sophisticated neurophysiological technique. 

Lipids can combine with carbohydrates or proteins to form glycolipids and lipoproteins. These will be examined in greater detail in Combo Circle. 

These proteins are composed of simple proteins in combination with carbohydrates like mucopolysaccharides, which include hyaluronic acid and chondroitin sulphates. On hydrolysis, mucopolysaccharides yield more than 4% of amino-sugars, hexosamine and uronic acid e.g., ovomucoid from egg white. Soluble mucoproteins are neither readily denatured by heat nor easily precipitated by common protein precipitants like trichloroacetic acid or picric acid. The term glycoproteins is restricted to those proteins that contain small amounts of carbohydrate usually less than 4% hexosamine. 

An important biosynthetic pathway leads from amino acids to proteins, alkaloids, and purines, and the latter, in combination with carbohydrates and inorganic phosphate, form the vital nucleic acids. 

Lipids are seldom found free in nature and they are invariably combined with carbohydrates or proteins, which then form macro-molecular bio-complexes (Gurr and James, 1971). Before achieving an understanding of such systems, the chemical and physical properties of the simpler lipid components need to be investigated in order to determine how lipids interact with other molecules. 

Belhadj A, Telef N, Saigne C, Cluzet S, Barrieu F, Hamdi S, Merillon JM (2008) Effect of methyl jasmonate in combination with carbohydrates on gene expression of PR proteins, stilbene and anthocyanin accumulation in grapevine cell cultures. Plant Physiol Biochem 46 493 99. doi 10.1016/j.plaphy.2007.12.001... 

In recent years, soy products such as soy whole flour (SF), soy protein concentrate (SPC), and soy protein isolate (SPI) have been considered as alternatives to petroleum polymers because of their abundance, low cost, perfect adhesion, and good biodegradability (Maruthi et al. 2014). SF contains about 40-60 % protein, combined with fats and carbohydrates. Soy protein concentrate contains about 60-70 % protein. SPI contains more than 90 % of protein and is the most widely used soybean product for film processing (Ciannamea et al. 2014). Moreover, SPI-based films are clearer, smoother, and more flexible compared to other plant protein-based films, and they have impressive gas barrier properties compared to those prepared from lipids and polysaccharides. When SPI films are not moist, their O2 permeability was 500, 260, 540, and 670 times lower than that of films based on low-density polyethylene, methylceUulose, starch, and pectin, respectively (Song et al. 2011). Thus, in addition to their large availability, soy protein-based materials have interesting barrier and release properties ideal for packaging applications. 

Definitive location of pigment in the cell wall or in the plasma membrane has been difficult because clean preparations of either structure have not yet been obtained. Within the bacterial cell, prodigiosin is probably bound to protein (Linnane and Still, 1955), perhaps in combination with carbohydrate and Upid (PuRKAYASTHA and WiLLiAMS, unpubUshed). 

Protein concentration can be determined by using method of Bradford,9 which utilises Pierce reagent 23200 (Pierce Chemical Company, Rockford, IL, USA) in combination with an acidic Coomassie Brilliant Blue G-20 solution to absorb at 595 nm when reagent binds to the protein. A 20 mg/1 bovine serum albumin (Pierce Chemical) solution was used as the standard. Starch concentration was measured by the orcinol method4,9-11 using synthetic starch as the reference. A yellow to orange colour is obtained and measured at 420 nm when orcinol reacts with carbohydrates. Absorbance is determined by spectrometry. 

Combination of Whey Proteins with Carbohydrates. Journal of Dairy Science, Vol.76, No. 1, (October 1993), pp.2878-2885, ISSN 0022-0302. 

Extraction of PHA from plants is likely to be a major factor affecting the production cost of PHA from crops and, therefore, the economic viability of this approach. In contrast to production of PHA from bacterial fermentation, where the production system is designed to produce only PHA, an agricultural production of PHA is likely to be most viable only through the recovery of not only PHA but also all other useful components of the harvested crop, i.e., oil, proteins, and carbohydrates. This fact, combined with the lower level of PHA accumulation in plants in comparison to micro-organism, is likely to make PHA recovery from plants a challenging task. 

Heparin is a carbohydrate-based (glycosaminoglycan) anticoagulant associated with many tissues, but mainly found stored intracellularly as granules in mast cells that line the endothelium of blood vessels. Upon release into the bloodstream, heparin binds to and thereby activates an additional plasma protein, namely antithrombin. The heparin-antithrombin complex then binds a number of activated clotting factors (including Ha, IXa, Xa, XIa and Xlla), thereby inactivating them. The heparin now disassociates from the complex and combines with another antithrombin molecule, thereby initiating another turn of this inhibitory cycle. 

The phosphoproteins and the nucleoproteins contain also the element phosphorus in the former, probably combined directly with one of the constituents of the protein molecule in the latter, combined with a purine base or a carbohydrate, which substances constitute nucleic acid. 

Riboflavin (vitamin B2) is found in liver, milk, meat, green vegetables, cereals and mushrooms. It is active in the form of two coenzymes, flavin mononucleotide and flavin adenine dinucleotide. As a coenzyme for proton transfer in the respiratory chain it is indispensable for energy-release from carbohydrates, lipids and proteins. Riboflavin deficiency only occurs in combination with deficiencies of other members of the vitamin B family. The symptoms of such deficiency consist of angular stomatitis, lesions of the cornea, dermatoses and normochromic normocytic anaemia. 

Proteins composed solely of amino acid units are referred to as simple proteins. Many proteins contain other chemical groups in addition to amino acids. These proteins are called conjugated proteins. Proteins containing a carbohydrate unit are called glycoproteins, those with a nucleic acid are called nucleoproteins, and those combined with a lipid are called lipoproteins. High-density lipoproteins (HDLs) and low-density lipoproteins (LDLs) are included in a cholesterol test. LDLs, which... 

Myeloma proteins occur in animal tumors of various types. The synthesis of these proteins can be induced in some experimental animals by injection of mineral oil, or the implantation of plastic discs.161 Myeloma proteins were shown to possess antibody activity, with specificity for different types of substances.161 Some of these proteins were found to combine with such carbohydrates as bacterial, cell-wall polysaccharides, lipopolysaccharides, dextrans, levans, and galactans.162 Myeloma proteins that combine with galactans or dextrans possess anti-galactan activity,163,164 or anti-dextran activity,165-167 and have been studied most extensively. 

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