Polymers DNA and

Like proteins, the nucleic acids are polymers. DNA and RNA are each composed of four different monomers, just as proteins are composed of 20 different monomers. These are called nucleotides. 

Basic nitrogen compounds similar to the plant alkaloids also occur in animals, although the description animal alkaloid seldom is used. Certain amines and ammonium compounds play key roles in the function of the central nervous system (Figure 23-3) and the balance of amines in the brain is critical for normal brain functioning. Also, many essential vitamins and hormones are basic nitrogen compounds. Nitrogen bases also are vital constituents of nucleic acid polymers (DNA and RNA) and of proteins (Chapter 25). 

The main driving force behind the chemistry of nucleotides and nucleic acids continues to be the demand for novel chemotherapeutics. Over the past few years this motivation has extended from the traditional small nucleotide drugs to the bio-polymers DNA and RNA and more importantly their modified analogues. In addition, the understanding of recognition processes involving nucleic acids, with each other, proteins and small molecules is an area of considerable interest which spans from structural studies, such as NMR and crystallography, to the synthesis of modified nucleotides and nucleic acids. Since this review did not appear last year we have endeavoured to include some material form early 1993 and therefore cover publications from January 1993 to June 1994. 

Nucleic acids, in the form of the huge polymers DNA and RNA, are central to the genetic machinery of cells. 

Polymalatase may be useful for the tayloring of /3-poly(malic acid) and its derivatives, and for analytical purposes. If the hydrolase is arrested at points of polymer branches or covalently/physically attached ligands, the hydrolase can be used in studies analogous to those known for DNA and exonucleases. 

Kinoshita, Imoto etal.11 14) synthesized other anionic models, 5 (APVP), CPVP, UPVP, TPVA, HPVA, THPVA, and 6 (AMPPVA), by the polymer reaction of N-eoupled(2-dihydrogenphosphate)-ethylderivatives of nucleic acid bases (or adenosine-5 -phosphate, AMP) with polyvinylaleohol. A, C, U, T, H, and TH denote adenine, cytosine, uracil, thymin, hypoxanthine, and theophylline, respectively. The authors reported the apparent hypochromities of 3 to 16% for many kinds of mixtures of the models and DNA or RNA, as compiled in Table 1. However, for the mixtures APVA + RNA, HPVA + RNA HPVA + DNA, THPVA + RNA, CPVA + DNA and CPVA + RNA, no hypochromicity was detected. 

Uchegbu and coworkers have studied the complexation and delivery of DNA using a unique poly(amino acid)-based polymer vesicle. A polymer of either poly (L-lysine) or poly(L-omithine) was functionalized with methoxy-poly(ethylene glycol) (mPEG) and hydrophobic palmitic acid chains to synthesize an amphiphilic triblock of either mPEG-6-poly(L-lysine)-6-palmitoyl or mPEG-Z>-poly(L-omithine)-6-palmitoyl. Vesicles formed from these polymers were complexed with DNA and showed improved transfection in vitro over poly(amino acid) complexed with DNA or DNA alone [82]. 

Due to its unique chemical composition and structure, DNA can interact with a plethora of chemical structures via numerous types of bonds. This property ultimately defines the ability of DNA fragments to serve as the building blocks in the complex three-dimensional self-assembled structures. Following we Ust four major types of polymer/DNA interactions that can lead to formation of supramolecular structures ... 

DNA is ideally suited as a structural material in supramolecular chemistry. It has sticky ends and simple rules of assembly, arbitrary sequences can be obtained, and there is a profusion of enzymes for modification. The molecule is stiff and stable and encodes information. Chapter 10 surveys its varied applications in nanobiotechnology. The emphasis of Chapter 11 is on DNA nanoensembles, condensed by polymer interactions and electrostatic forces for gene transfer. Chapter 12 focuses on proteins as building blocks for nanostructures. 

The remarkable enhancement of steady state fluorescence emission intensity and quantitative data on fluorescence quanfum yield was sequence-dependenf, being maximum wifh AT-rich DNA and alternating AT polymer (Fig. 6b). 

Capillary gel electrophoresis is becoming very widely used in the biotechnology field for the high resolution separation of DNA and peptides according to molecular weight, but it has limited application for the analysis of surfactants (Wallingford, 1996). CGE does result in an increase in the resolution per unit time over SEC for charged polymers (Poli and Schure,1992). 

In Chapters 3 and 4, we referred to the basic reactions leading to the classes of biological polymers DNA (RNA), proteins, saccharides and long-chain hydrocarbons. Each class has a specific functional value. Here we shall not comment further on the special properties these polymers introduce in aiding cell survival including... 

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