Blood protein composition

Studies have been conducted for the intactness of biological fluids after photochemical treatment, in particular, proteins of allantoic fluid and blood semm, by methods of spectrophotometry and gel electrophoresis. The growth properties of semm were evaluated in cell culture. The protein composition of biological fluid was shown not to undergo dramatic changes during the course of photodynamic inactivation of vimses. 

The plasma lipoproteins are spherical macromolecular complexes of lipids and specific proteins (apolipoproteins or apoproteins). The lipoprotein particles include chylomicrons, very-low-density lipoproteins (VLDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL). They differ in lipid and protein composition, size, and density (Figure 18.13). Lipoproteins function both to keep their component lipids soluble as they transport them in the plasma, and also to provide an efficient mechanism for transporting their lipid contents to (and from) the tissues. In humans, the transport system is less perfect than in other animals and, as a result, humans experience a yradual deposition of lipid—especially cholesterol—in tissues. This is a potentially life-threat-en ng occurrence when the lipid deposition contributes to plaque formation, causing the narrowing of blood vessels (atherosclerosis). 

Shulman, G.E. and Kulikova, N.I. (1966). On the specificity of protein composition of blood serum in fish (In Russian). Uspekhi Sovremennoy Biologii 62,42-60. 

The cells lining the lumen of the intestine are polarized, that is they have two distinct sides or domains which have different lipid and protein compositions. The apical or brush border membrane facing the lumen is highly folded into microvilli to increase the surface area available for the absorption of nutrients. The rest of the plasma membrane, the basolateral surface, is in contact with neighboring cells and the blood capillaries (Fig. 5). Movement between adjacent epithelial cells is prevented by the formation of tight junctions around the cells near the apical domain. Thus any nutrient molecules in the lumen of the intestine have to pass through the cytosol of the epithelial cell in order to enter the blood. 

The liver is responsible for modifying blood protein and Aa composition, which it performs by a series of enzymatic process including transamination, deamination and reamination. The essential aromatic amino acids are degraded in the liver, whereas the branched-chain amino acids are passed to the periphery, where they are metabolised exclusively by skeletal muscle. Non-essential amino acids may be metabolised hepatically or in skeletal muscle. 

DSC has been used to study the individual protein components of biological membranes of relatively simply protein composition and the interaction of several of these components with lipids and with other proteins. The red blood cell membrane, which has been most intensively studied, exhibits five discrete protein transitions, each of which has been assigned to a specific membrane protein. The response of each of these thermal transitions to variations in temperature and pH as well as to treatment with proteases, phospholipases, specific labelling reagents, and modifiers and inhibitors of selected membrane activities, has provided much useful information on the interactions and functions of these components in the intact erythrocyte membrane (46-49). Similar approaches have been applied to the bovine rod outer segment membrane (50) and to the spinach chloroplast thylakoid membrane (51). 

Blood and plasma viscosity fall by 5-10% during the administration of coumarins in healthy volunteers and in patients with coronary artery disease (36). This may also explain, at least partly, the antianginal effect of coumarins. The mechanism might be related to changes in the protein composition of the plasma. 

L. H. Laasberg and J. Hedley-Whyte. Halothane solubility in blood and solutions of plasma proteins effects of temperature, protein composition, and hemoglobin concentration. Anesthesiology, 32, 351-6(1970)... 

Lipoproteins complexes are soluble aggregates of lipids and proteins that transport lipids through the blood and lymph. Despite their differences in lipid and protein composition, all lipoproteins share common structural features, notably a spherical shape that can be detected by electron microscopy. The lipoproteins help maintain in solubilized form some 500 mg of total lipid per 100 mL of human blood in the postabsorptive state, after the contents of a meal have been digested and absorbed into the bloodstream. 

For the construction of artificial metalloproteins, protein scaffolds should be stable, both over a wide range of pH and organic solvents, and at high temperature. In addition, crystal structures of protein scaffolds are crucial for their rational design. The proteins reported so far for the conjugation of metal complexes are listed in Fig. 1. Lysozyme (Ly) is a small enzyme that catalyzes hydrolysis of polysaccharides and is well known as a protein easily crystallized (Fig. la). Thus, lysozyme has been used as a model protein for studying interactions between metal compounds and proteins [13,14,42,43]. For example, [Ru(p-cymene)] L [Mn(CO)3l, and cisplatin are regiospecificaUy coordinated to the N = atom of His 15 in hen egg white lysozyme [14, 42, 43]. Serum albumin (SA) is one of the most abundant blood proteins, and exhibits an ability to accommodate a variety of hydrophobic compounds such as fatty acids, bilirubin, and hemin (Fig. lb). Thus, SA has been used to bind several metal complexes such as Rh(acac)(CO)2, Fe- and Mn-corroles, and Cu-phthalocyanine and the composites applied to asymmetric catalytic reactions [20, 28-30]. 

Not less interesting was also the effect of saline infusions on the composition of blood proteins (104), because such infusions may cause an outflow of the tissue reserve of proteins into the circulation (26 children). Our observations, made with various infusions and transfusions, allow the conclusion that transfusions of blood or plasma are an important factor, bringing about favorable changes in blood proteins in the course of rehydration treatment. They not only level up the decreased values we saw, moreover, in individual cases very marked changes in blood proteins. These changes were manifested both in the composition of the fractions and their quality, or denaturation capability, and were probably caused... 

However, NIR specua are distinctive for proteins in the blood vessel wall (specifically collagens and elastin). The ability of NIR specuometry to collect useful spectra in aqueous environments may make it useful for proteomics in vivo. The results of this study suggest that NIR spectroscopy is a potentially useful technique for investigating vascular changes and protein composition associated with AAA in a mouse model of this disease. These results support an expanded study in the future to correlate NIR spectra with chemical compositions and histological features in aortic aneurysm, which is known to often be associated with atherosclerosis. 

The protein composition and distribution on the blood contacting surface of MPC copolymers from human plasma has been determined by radioimmunoassay and an immunogold labeling technique (8). In Fig. 5, proteins existed on the plasma contacting surface after 60 min contact with poly(MPC-co-BMA) and glass were determined by radioimmunoassay. On all materials, not only major components of plasma pro-... 

The protein composition of cereals is not snfflcient to sustain optimnm growth in most domestic animals. Thus, cereals are supplemented with protein meals that contain high amonnts of lysine and tryptophan. The most common protein meals are soybean, cottonseed, canola, and meat and fish meal. The use of meat and bone meal, and other animal protein meals snch as dried blood, is prohibited in several parts of the world because its consumption has been associated with mad cow disease. 

Legume forages, such as alfalfa or clover, are considered high quaHty, readily available protein sources. Animal sources of supplemental protein include meat and bone meal blood meal, 80% CP fish meal other marine products and hydroly2ed feathermeal, 85—90% CP. Additionally, synthetic amino acids are available commercially. Several sources (3,9,19) provide information about the protein or amino acid composition of feedstuffs. 

Casein. Milk contains proteins and essential amino acids lacking in many other foods. Casein is the principal protein in the skimmed milk (nonfat) portion of milk (3—4% of the weight). After it is removed from the Hquid portion of milk, whey remains. Whey can be denatured by heat treatment of 85°C for 15 minutes. Various protein fractions are identified as a-, P-, and y-casein, and 5-lactoglobulin and blood—semm albumin, each having specific characteristics for various uses. Table 21 gives the concentration and composition of milk proteins. 

The composition of body fluids remains relatively constant despite the many demands placed on the body each day. On occasion, these demands cannot be met, and electrolytes and fluids must be given in an attempt to restore equilibrium. The solutions used in the management of body fluids discussed in this chapter include blood plasma, plasma protein fractions, protein substrates, energy substrates, plasma proteins, electrolytes, and miscellaneous replacement fluids. Electrolytes are electrically charged particles (ions) that are essential for normal cell function and are involved in various metabolic activities. This chapter discusses the use of electrolytes to replace one or more electrolytes that may be lost by the body. The last section of this chapter gives a brief overview of total parenteral nutrition (TPN). 

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