Proteins nucleoprotein

Muscle. Binding of drugs to components within the muscle may create the long-term storage of these compounds. Various agents may be actively transported into the muscle cell and may form reversible bonds to intracellular structures such as proteins, nucleoproteins, or phospholipids. An example is the antimalarial drug quinacrine. 

Nucleoproteins are composed of simple proteins, generally protamins, histones, or albumins, and a nucleic acid. They are the chief constituents of the cell nuclei, and in those organs especially rich in cells, such as the thymus and the lymph glands, exceed in quantity all other proteins. Nucleoproteins... 

Aside from whether they are directly active per se, or merely as precursors of active metabolic intermediates, carcinogenic polycyclic hydrocarbons can initiate carcinomas (e.g. epithelioma) at the point of application on the skin (the commonest mode of study), or can lead to distant tumours, as in bronchogenic cancer [23]. The mechanism probably includes solubilisation of the carcinogens (by proteins, nucleoproteins, fatty acid esters, etc. or even in aqueous solution [58]), so as to enable them to traverse the dermis (possibly via an external solvent) and thus react in the epidermis, which possesses a lipoid barrier. Alternatively, appendageal transport routes (hair follicles, sweat glands, sebaceous glands) may be used [59]. When carcinogens act at a distance, as with liver, breast, bladder and other internal cancers, an internal transport mechanism or medium is evidently needed. 

Whether complexing or reaction of the carcinogen in the cell is responsible for tumorigenesis, the nature of the cellular target protein, nucleoprotein, desoxyribonucleic acid (DNA), ribonucleic acid (RNA), histone, or other cellular moiety - is unknown. While previous reviews have covered investigations into cellular mechanisms in general [11, 22, 35, 44, 105,106], the present review is confined to polycyclic aromatic hydrocarbons. 

NUCLEOPROTEINS. Nucleoprotein conjugates have many roles in the storage and transmission of genetic information. Ribosomes are the sites of protein synthesis. Virus particles and even chromosomes are protein-nucleic acid complexes. 

The DNA in a eukaryotic cell nucleus during the interphase between cell divisions exists as a nucleoprotein complex called chromatin. The proteins of chromatin fall into two classes histones and nonhistone chromosomal proteins. 

Baltimore D (1988) Gene therapy. Intracellular immunization. Nature 335 395-396 Basta S, Stoessel R, Easier M, van den Broek M, Groettrup M (2005) Cross-presentation of the long-lived lymphocytic choriomeningitis virus nucleoprotein does not require neosynthesis and is enhanced via heat shock proteins. J Immunol 175 796-805 Baum C (2007) Insertional mutagenesis in gene therapy and stem cell biology. Curr Opin Hematol 14 337-342... 

In terms of their molecular structures, the nucleotide and protein realms are usually considered to be rather independent of each other. However, these two families of molecules are covalently linked in the translational aminoacyl- RNAs and ribonucleoproteins as well as in the nucleoproteins involved in cellular and viral replication. In these hybrid biomolecules, a (deoxy)ribose phosphate moiety serves as the structural connection between the nucleoside and peptide moieties. 

A ribosome is a cytoplasmic nucleoprotein stmcture that acts as the machinery for the synthesis of proteins from the mRNA templates. On the ribosomes, the mRNA and tRNA molecules interact to translate into a specific protein molecule information transcribed from the gene. In active protein synthesis, many ribosomes are associated with an mRNA molecule in an assembly called the polysome. 

In addition to its coenzyme role, NAD is the source of ADP-ribose for the ADP-ribosylation of proteins and polyADP-ribosylation of nucleoproteins involved in the DNA repair mechanism. 

Telomeres are the nucleoprotein assembUes at the ends of chromosomes that comprise guanine-rich tandem-repeating DNA sequences (the size of a typical telomere is aroimd 6-12 kb in length in hiunans) together with a number of structural and regulatory proteins. The major function of telomeres is to protect chromosome ends from base-pair loss and end-to-end fusions, thereby safeguarding the integrity of each chromosome [10, llj. The enzyme... 

The chromosome structure is visible only during the mitotic portion of the cell cycle. The constituent parts of the chromosomes are nucleoprotein fibers called chromatin. When condensed, chromatin forms a microscop-ically visible chromosome-like structure. The chromosomes are composed of DNA, RNA, and proteins. The relative amounts of the three vary, but chromatin is primarily protein and DNA. 

Kenner, R. A. and Aboderin, A. A. (1971). A new fluorescent probe for protein and nucleoprotein conformation. Binding of 7-(p-Methoxyben-zylamino) -4-nitrobenzoxadiazole to bovine trypsinogen and bacterial ribosomes. Biochemistry 10, 4433 1440. 

In addition to small organic molecules or metal ions, proteins may have other components tightly associated with them. Nucleoproteins, for instance, contain noncovalently bound DNA or RNA, as in some of the structural proteins of viruses. Lipoproteins contain associated lipids or fatty acids and may also carry cholesterol, as in the high-density and low-density lipoproteins in serum. 

Shetty, J.K., and Kinsella, J.E. (1980) Ready separation of proteins from nucleoprotein complexes by reversible modification of lysine residues. Biochem. J. 191, 269-272. 

Four processes are concerned in the isolation of a nucleic acid. First is the destruction of the tissue structure (stage 1). A nucleoprotein complex is then separated from other cellular constituents (stage 2). This complex is dissociated and the protein is removed (stage 3) and, finally, the nucleic acid is precipitated from the resulting solution (stage 4). Disintegration of... 

In a number of methods, isolation of the nucleoprotein complex (stage 2) is avoided. In the isolation of ribonucleic acid from beef pancreas,1241 nuclear material and cell debris are removed from a normal-saline extract of the minced tissue, which is then brought to half-saturation with sodium chloride (to dissociate the protein from the nucleic acid). After removal of the protein, the nucleic acid is precipitated with alcohol. However, the suggestion has been made126 that it is more satisfactory to isolate the nucleoprotein first, and this has been carried out, for instance, in the extraction of the ribonucleic acid from fowl sarcoma GRCH 15.126 Nucleoprotein complexes have also been isolated from baker s yeast127 and have been separated into various fractions, the nucleic acids from which differ slightly in composition. In addition, nucleoproteins have been isolated by complex formation with cetyltrimethylammonium bromide.128... 

In the past, dissociation of the nucleoprotein complex has been brought about by salt solutions or by heat denaturation,129 but, more recently, decomposition has been effected by hydrolysis with trypsin,126 or by the use of dodecyl sodium sulfate130 or strontium nitrate.131 Some virus nucleoproteins are decomposed by ethyl alcohol.132 This effect may be similar to that of alcohol on the ribonucleoproteins of mammalian tissues. If minced liver is denatured with alcohol, and the dried tissue powder is extracted with 10% sodium chloride, the ribonucleoproteins are decomposed to give a soluble sodium ribonucleate while the deoxyribonucleoproteins are unaffected.133 On the other hand, extraction with 10 % sodium chloride is not satisfactory unless the proteins have first been denatured with alcohol. Denaturation also serves to inactivate enzymes of the tissues which might otherwise bring about degradation of the nucleic acid during extraction. 

Yusibov et al. [71] delivered to 14 human volunteers spinach expressing epitopes from the rabies virus glycoprotein and nucleoprotein fused to the coat protein of alfalfa mosaic virus (AlMV). Five of the fourteen subjects had previously received a... 

Bouteille M, Dupuy-Coin AM, Moyne G. Techniques of localization of proteins and nucleoproteins in the cell nucleus by high resolution autoradiography and cytochemistry, in Methods in Enzymology (O Malley BW, Hardman JG, eds.), Academic Press, New York, 1975, pp. 3-41. 

Aminoacyl-tRNA synthetases Degradation of proteins, peptides, and glycopeptides Nucleoproteins Protein modification... 

DNA is packaged in the nucleus into the form of chromatin. Chromatin is a nucleoprotein complex composed of histone and non-histone proteins, DNA and RNA and it exhibits a repeating structure (van Holde, 1988). The basal unit of chromatin, the nucleosome, is composed of a histone octamer (two each of H2A, H2B, H3 and H4) around which two superhelical turns of DNA are wrapped (van Holde, 1988). The structure of both the histone octamer (Arents et al, 1991)... 

The genetic information of eukaryotic cells is propagated in the form of chromosomal DNA. Besides the nucleic acid component, chromosomes contain architectural proteins as stoichiometric components, which are involved in the protective compaction of the fragile DNA double strands. Together, the DNA and proteins form a nucleoprotein structure called chromatin. The fundamental repeating unit of chromatin is the nucleosome core particle. It consists of about 147 base pairs of DNA wrapped around a histone octamer of a (H3/H4)2 tetramer and two (H2A-H2B) heterodimers. One molecule of the linker histone HI (or H5) binds the linker DNA region between two nucleosome core particles (Bates and Thomas 1981). 

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