Adenine molecular structure

Figure 2.10 (a) Molecular structure and atomic numbering of adenine, (b) The calculated model of the adenine-silver quadrimer complex, (c) The calculated frequency shifts /Irbm of the Ad-N3 Ag quadrimer and the calculated binding energy as a function of the bond distance for the Ag-N linkage. 

Figure 23 Molecular structure of the complex cation containing adenine and thymine.

Nowak, M. J., L. Lapinski, J. S. Kwiatkowski, and J. Leszczynski. 1996. Molecular Structure and Infrared Spectra of Adenine—Experimental Matrix Isolation and Density Functional Theory Study of Adenine N-15 Isotopomers. J. Phys. Chem. 100, 3527. 

Figure 3.1 Amino add side-chain groups involved in binding NAD at the active site of an enzyme. The enzyme is glyceraldehyde dehydrogenase. More than 20 amino acids, the position of which in the primary structure is indicated by the number, counting from the N-terminal amino acid, are involved in the binding. This emphasises the complexity of the binding that is responsible for the specificity of the enzyme for NAD (depicted in bold). The molecular structure of nicotinamide adenine dinucleotide (NAD ) provided in Appendix 3.3.

The two strands of DNA are held together by the molecular attractions that occur between nucleotides. Because of their molecular structures, however, the nucleotides are particular in the attractions they have for each other. Guanine and cytosine, for example, are best attracted to each other, while adenine and thymine are best attracted to each other. Accordingly, within the DNA double helix for each adenine on one strand there is a thymine on the opposing strand to which it is attracted. The number of adenines and thymines in DNA, therefore, is always the same. 

O.S. Sukhanov et al., Molecular structure and hydrogen bonding in polyhydrated complexes of adenine A DFT study. J. Phys. Chem. B 107, 2846-2852 (2003)... 

Sakore TD, Sobell HM (1969) Crystal and molecular structure of a hydrogen-bonded complex containing adenine and hypoxanthine derivatives 9-ethyl-8-bromoadenine 9-eth-yl-8-bromohypoxanthine. J Mol Biol 43 77-87... 

Fig. 9.5 The molecular structures of DNA and RNA components the purine bases adenine and guanine, the pyrimidine bases cytosine, thymine and uracil and the structure of riboso-monophosphates.

Fig. 4 Molecular structure of two-centered hydrogen bonds (A = adenine T = thymine G = guanine C = cytosine)...

The molecular structure of the MPT pore is not fully understood either. Current evidence suggests that two proteins, the voltage-dependent anion channel (VDAC), located in the outer mitochondrial membrane, and the adenine nucleotide translocase (ANT-1), located in the inner mitochondrial membrane, combine to form a pore that spans both membranes. 

Perutz, Max F. (1914-2002). An Austrian molecular biologist who was a recipient of the Nobel Prize for chemistry in 1962 along with Kendrew. His work was concerned with crystalline protein structure, particularly the molecular structure of hemoglobin and myoglobin, nicotinamide adenine dinucleotide was educated in England and Austria. 

One of a number of basic compounds found in living matter and having a purine-type molecular structure. See adenine base pair guanine hypoxanthine xanthine uric acid caffeine theobromine. 

Figure 18. A, Molecular structure of adenosine-S -mononicotinate showing the facility with which the two bases can stack. B, Temperature study of the circular dichroism of adenosine-5 -mononicotinate. A reciprocal relation is seen between the 260 nm band of adenine and the band near 270 mn of the nicotinate chromophore as the two aromatic chromophores stack at lower temperatures. Reproduced, with permission, from [31].

DNA encodes the information needed to make proteins in the form of triplets of bases (codons), for example thymine-adenine-cytosine (TAG) in the diagram below. As RNA is synthesized from DNA, these are turned into complementary codons (in the example below, AUG) by pairing up the bases as shown on p. 1138. This RNA forms the instructions for protein synthesis by the ribosome—perhaps the most elaborate molecular structure in the known universe. Each codon of the RNA chain tells the ribosome to add a specific amino acid to the growing protein. For example, the codon AUG indicates methionine, which we met as a component of SAM. Methionine is a typical amino acid of the kind present in proteins, but is also the starter unit of all proteins. 

Fig. 24 (a) Molecular structure of poly(thymine acrylate-i>-n-butyl acetate-b-adenine acrylate) triblock copolymers (PTBA). (b) Dynamic mechanical temperature ramp of PTBA and copolymer controls. Reproduced from [141] with permission of The Royal Society of Chemistry. Copyright 2014... 

FIGURE 1 Molecular structure of DNA. From top to bottom Adenine-Thymine. Guanine-Cytosine, Adenine-Thymine and Guanine-Cytosine. (From Schanfield, M. S. (2000). Deoxyribonucleic Acid/Basic Principles. In Encyclopedia of Forensic Sciences (Siegel, J. A.. Saukko, P. J., and Knupfer, G. C.. eds.). Academic Press, London, p. 481.)... 

Not only do the I Ching hexagrams correspond to the DNA genetic code [16], but the Ho Tu dots have also been shown to symbolize the molecular structure of the two H-bonded base pairs. The two base pairs are made up of 55 atoms, just like the Ho Tu consists of 55 dots. The dots above the diagonal in Fig. 3 model the cytosine-guanine pair, and those below the diagonal represent adenine-thymine, as drawn. 

The mechanisms by which the nucleobases return to the groimd state are subtly connected to the molecular structure of these bases. For instance, simple tautomerization of adenine into 2-aminopurine results in an increase of excited-state lifetime from 1.1 to 30 ps (Canuel et al. 2005). Methyl-substitution of cytosine or cytidine at Cs position increases the lifetime in water solution by a factor of seven (Malone et al. 2003). Fluoro-substitution at the same site or acetyl-substitution at N4 have even larger effects, increasing the lifetime from Ips to, respectively, 88 and 280 ps (Malone et al. 2003). Double methyl substitution in positions Ni and N3 of thymine increases its lifetime in gas phase from 5 ps (Canuel et al. 2005) to about 150 ps (He et al. 2003). Similar effects were also reported for single and double methyl substitutions in macil (He et al. 2003). 

Zhang, Y., Huang, K. X. (2007). The influence of the hydrated metal cations binding to adenine-N7 or adenine-N3 on the hydrogen bonding in adenine-thymine base pair A comparative study. Journal of Molecular Structure Theochem, 822, 57. 

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