Protein Enzyme Hormones

Electrophoresis on a macro scale has been applied to a variety of difficult analytical separation problems inorganic anions and cations, amino acids, catecholamines, drugs, vitamins, carbohydrates, peptides, proteins, nucleic acids, nucleotides, polynucleotides, and numerous other species. A particular strength of electrophoi esis is its unique ability to separate charged macromolecules of interest to biochemists, biologists, and clinical chemists. For many years, electrophoresis has been the powerhouse method of separating proteins (enzymes, hormones, antibodies) and nucleic acids (DNA, RNA), for which it offers unparalleled resolution. ... 

During the long passage of inorganic components of foodstuffs, water and air through the fauna (and man), which has lasted for several hundred million of years, the majority of these substances have most likely become parts or activators of proteins, enzymes, hormones or other essential components of the body. Consequently, either a deficiency or a toxic excess in supply must be considered for most elements (Figure 3.1). 

Elements usually interact as constituents of macromolecules (proteins, enzymes, hormones, etc.) or according to their oxidation state. Thus, only problem-related speciation analysis promises to become a key for useful risk assessment of elements in the environment. Also activities such as diagnosis and therapy, as well as the depletion of trace elements, optimum levels of essential elements or toxicity of trace elements, will be estimated more reliably. 

In the following sections, we describe research regarding the dehvery of proteins, including model proteins, enzymes, hormones, growth factors, and cytokines, from the atrigel system. (A listing of the proteins studied in this system is presented in Table I). The methods ofprotein analysis and the factors used to control release kinetics are summarized. In addition, in vitro and in vivo systems employed to determine bioactivity of protein formulations are presented. The imphcations regarding the controlled dehvery of proteins are discussed. 

The most striking thing about proteins is the diversity of their roles m living sys terns siUc is a protein skin and hair are mostly proteins many hormones are proteins a protein carries oxygen from the lungs to the tissues where it is stored by another pro tern and all enzymes are proteins... 

Proteins. The most abundant and physiologically diverse natural biopolymers are proteins, which make up enzymes, hormones, and stmctural material such as hair, skin, and connective tissue. The monomer units of natural proteins, a-amino acids, condense to form dipeptides, tripeptides, polypeptides, and proteins. 

Figure 10.1 ThecyclicAMPsecondmessengersystem.Themostcommonsecond messenger system activated by the protein/peptide hormones and the catecholamines involves the formation of cAMP. This multistep process is initiated by binding of the hormone (the first messenger) to its receptor on the cell surface. The subsequent increase in the formation of cAMP (the second messenger) leads to the alteration of enzyme activity within the cell. A change in the activity of these enzymes alters cellular metabolism.

Steroid hormones and thyroid hormone carry out their effects by way of gene activation. In contrast to the protein/peptide hormones, which alter existing enzyme activity, these hormones induce the synthesis of new enzymes that then influence cellular metabolism. 

Proteins such as antibodies, enzymes, hormones and vaccine antigens can be used to prevent, diagnose and treat a range of diseases. Such molecules are therefore of paramount importance in health and medicine. Historically, many of these proteins have been isolated from human or animal sources. However, the low quantities present in such source material coupled with safety risks and high purification costs have limited the availability of protein therapeutics and vaccines for many types of disease. 

The pigment, P(s), can, in principle, be any seawater-soluble particulate solid that is being considered for a potential use in a self-polishing antifouling paint. Salts, sugars, and proteins (enzymes, peptides, or hormones) are obvious examples. It should be noted that the pigment can also represent a seawater-... 

Skelley et al (1973) listed a number of substances that may be determined quantitatively by the help of the RIA method, namely nucleic acids, proteins, enzymes, prostaglandins, steroidal hormones, antibodies, cancer and viral antigens, vitamins, and drugs together with their respective metabolites. 

The mechanisms of most drugs involve binding of the drug to a receptor. A receptor may be any macromolecular target, but the most common receptors are proteins. These include membrane proteins, enzymes, transporters, and structural elements. Some of the main receptors of interest for psychopharmacology are receptors for neurotransmitters and hormones, which show a high degree of selectivity. 

Many enzymes are glycoproteins, as are many receptors, transport proteins, and hormones. They form an integral part of the membranes of mammalian cells. 

M17. Miedema, K., Boelhouwer, J., and Otten, J. W., Determinations of proteins and hormones in serum by an immunoassay using antigen-enzyme conjugates. Clin. Chim. Ada 40, 187-192 (1972). 

What is most remarkable is that cells can produce proteins with strikingly different properties and activities by joining the same 20 amino acids in many different combinations and sequences. From these building blocks different organisms can make such widely diverse products as enzymes, hormones, antibodies, transporters, muscle fibers, the lens protein of the eye, feathers, spider webs, rhinoceros horn, milk proteins, antibiotics, mushroom poisons, and myriad other substances having distinct biological activities (Fig. 3-1). Among these protein products, the enzymes are the most varied and specialized. Virtually all cellular reactions are catalyzed by enzymes. 

FIGURE 23-22 The composition of blood. Whole blood can be separated into blood plasma and cells by centrifugation. About 10% of blood plasma is solutes, of which about 10% consists of inorganic salts, 20% small organic molecules, and 70% plasma proteins. The major dissolved components are listed. Blood contains many other substances, often in trace amounts. These include other metabolites, enzymes, hormones, vitamins, trace elements, and bile pigments. Measurements of the concentrations of components in blood plasma are important in the diagnosis and treatment of many diseases. 

Affinity chromatography can be applied to the isolation and purification of virtually all biological macromolecules. It has been used to purify nucleic acids, enzymes, transport proteins, antibodies, hormone receptor proteins, drug-binding proteins, neurotransmitter proteins, and many others. 

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