Proteins hemoglobin

PSS-SG composite film was tested for sorption of heme proteins hemoglobin (Hb) and myoglobin (Mb). The peroxidaze activity of adsorbed proteins were studied and evaluated by optical and voltammetric methods. Mb-PSS-SG film on PG electrode was shown to be perspective for detection of dissolved oxygen and hydrogen peroxide by voltammetry with linear calibration in the range 2-30 p.M, and detection limit -1.5 p.M. Obtained composite films can be modified by different types of biological active compounds which is important for the development of sensitive elements of biosensors. 

The most conspicuous use of iron in biological systems is in our blood, where the erythrocytes are filled with the oxygen-binding protein hemoglobin. The red color of blood is due to the iron atom bound to the heme group in hemoglobin. Similar heme-bound iron atoms are present in a number of proteins involved in electron-transfer reactions, notably cytochromes. A chemically more sophisticated use of iron is found in an enzyme, ribo nucleotide reductase, that catalyzes the conversion of ribonucleotides to deoxyribonucleotides, an important step in the synthesis of the building blocks of DNA. 

FIGURE 5.13 Two basic types of biological transport are (a) transport within or between different cells or tissues and (b) transport into or out of cells. Proteins function in both of these phenomena. For example, the protein hemoglobin transports oxygen from the lungs to actively respiring tissues. Transport proteins of the other type are localized in cellular membranes, where they function in the uptake of specific nutrients, such as glucose (shown here) and amino acids, or the export of metabolites and waste products. 

The most important task of the red blood cells (erythrocytes) is to transport molecular oxygen (O2) from the lungs into the tissues, and carbon dioxide (CO2) from the tissues back into the lungs. To achieve this, the higher organisms require a special transport system, since O2 is poorly soluble in water. For example, only around 3.2 mb O2 is soluble in 1 L blood plasma. By contrast, the protein hemoglobin (Hb), contained in the erythrocytes, can bind a maximum of 220 mb O2 per liter—70 times the physically soluble amount. 

The last column in the table lists some of the functions of minerals. It should be noted that almost all of the macroelements in the body function either as nutrients or electrolytes. Iodine (as a result of its incorporation into iodothyronines) and calcium act as signaling substances. Most trace elements are cofactors for proteins, especially for enzymes. Particularly important in quantitative terms are the iron proteins hemoglobin, myoglobin, and the cytochromes (see p. 286), as well as more than 300 different zinc proteins. 

Many macromolecules (such as proteins) form stable monolayers at the water surface if the hydrophilic-lipohilic balance (HLB) is of the right quantity. Especially, almost all proteins (hemoglobin, ovalbumin, bovine serum albumin, lactoglobulin, etc.) are reported to form stable monolayers at the water surface. 

Erythrocytes—Red blood cells the color comes from the oxygen-carrying protein hemoglobin inside the cell. 

Red blood cells—Type of blood cell filled with the red protein hemoglobin that carries oxygen to tissues. 

L. B. Mendel and H. C. Bradley found in 1905 diat the snail syco-typus contains zinc in the fiver and in die oxygen-carrying protein of the blood, liemosycotypin. The diree respiratory proteins, hemoglobin of the vertebrates, hemocyanin of die octopus, and hemosycotypin of the... 

Figure 4. Binding of a protein (hemoglobin) to several tannin extracts (tannic acid, sugar maple tannins, yellow birch tannins, quebracho tannins see 29) at various pH values. Ranges of microbial chitinase activity, NPV activity, and Bt toxicity are given. See text for discussion and references.

FIGURE 3-1 Some functions of proteins, (a) The light produced by fireflies is the result of a reaction involving the protein luciferin and ATP, catalyzed by the enzyme luciferase (see Box 13-2). (b) Erythrocytes contain large amounts of the oxygen-transporting protein hemoglobin. (c) The protein keratin, formed by all vertebrates, is the chief structural component of hair, scales, horn, wool, nails, and feath-... 

Oxygen-Binding Proteins—Hemoglobin Oxygen Transport... 

Since solubility in blood is altered by many factors, including temperature, lipid level, protein, hemoglobin, and hemocrit values, the solubilities of the gases in the samples should be measured individually. This requires only a second equilibration of the original sample with a new aliquot of helium, and from the ratio of the chromatogram peak heights of the two extractions the solubility of the gas concerned can be calculated. 

An iron porphyrin is the prosthetic group in the oxygen transport and storage proteins, hemoglobin and myoglobin. Consequently there has been much interest in porphyrin complexes, especially of first row transition metals, as model systems for oxygen transport and storage. Much interest has also been shown in metal porphyrins as models for oxidases, in particular cytochrome P-450. 

Chemical equilibria are important in numerous biological and environmental processes. For example, equilibria involving O2 molecules and the protein hemoglobin play a crucial role in the transport and delivery of oxygen from our lungs to our muscles. Similar equilibria involving CO molecules and hemoglobin account for the toxicity of carbon monoxide. 

In clinical work many biological fluids have been submitted to paper electrophoretic separation. Serum and urine have been studied extensively and the results were reviewed in Volume I of this series (p. 238). Other fluids include cerebrospinal fluid (B12, B14, E6, K18), pleura] fluid (D4), gastric juice (H6), ascitic fluid (H9), synovial fluid (W3), proteins of the lens (F4, W9, W10), aqueous humor of the eye (W12, W24), edema liquid (W23), and pericardiac effusion (G2). Apart from the general separation of plasma proteins, work has been done on special protein groups, such as lipo- and glycoproteins, muco-proteins, hemoglobins (H19), coagulation factors (05), and on other components, such as amino acids. 

The role iron plays in the lives of humans is significant. Iron is primarily used in the production of steel, and it is an essential element in the human body, where it is part of the protein hemoglobin, which is responsible for carrying oxygen. Iron s two principal oxidation states are Fe (III) and Fe (II), and a complex cycle that is responsible for the conversions between the two forms exists in na-... 

Nyberg, F., Sanderson, K., and Glamsta, E.-L. 1997. The hemorphins a new class of opioid peptides derived from the blood protein hemoglobin. Biopolymers 43, 147-156. 

---