Macromolecules informational

The mechanism of carcinogenesis by PAHs is believed to involve alkylation of an informational macromolecule in a critical, but at present unknown, manner. Such an interaction with a protein has been modelled by alkylation of a peptide this showed a conformational change occurred on alkylation. It has not yet been possible to study the structure of DNA alkylated by an activated carcinogen this is because DNA is a fiber and the structural order in it is not sufficient for a crystal structure determination. However the crystal structures of some alkylated portions of nucleic acids are described, particularly some nucleosides alkylated by chloromethyl derivatives of DMBA. In crystals of these alkylation products the PAH portion of the adduct shows a tendency to lie between the bases of other nucleoside... 

Proteins and nucleic acids are informational macromolecules each protein and each nucleic acid has a characteristic information-rich subunit sequence. Some oligosaccharides, with six or more different sug-... 

Proteins are the most abundant of cellular components. They include enzymes, antibodies, hormones, transport molecules, and even components for the cytoskeleton of the cell itself. Proteins are also informational macromolecules, the ultimate heirs of the genetic information encoded in the sequence of nucleotide bases within the chromosomes. Structurally and functionally, they are the most diverse and dynamic of molecules and play key roles in nearly every biological process. Proteins are complex macromolecules with exquisite specificity each is a specialized player in the orchestrated activity of the cell. Together they tear down... 

Proteins are informational macromolecules, the ultimate heirs of the genetic information encoded in the sequence of nucleotide bases within the chromosomes. Each protein is composed of one or more polypeptide chains, and each peptide chain is a linear polymer of amino acids. The order of the amino acids commonly found in the polypeptide chain is determined by the order of nucleotides in the corresponding messenger RNA template. In this chapter we examine four aspects of protein metabolism (fig. 29.1) (1) The process whereby amino acids are ordered and polymerized into polypeptide chains (2) posttranslational alterations in polypeptides, which occur after they are assembled on the ribosome (3) the targeting process whereby proteins move from their site of synthesis to their sites of function and (4) the proteolytic reactions that result in the return of proteins to their starting material, amino acids. 

This complexity is due to the central role of nucleotides as energy currency, signaling molecules, and precursors to informational macromolecules in the cell. If the supply of nucleotides becomes limiting, cells couldn t make DNA or RNA, for example. Likewise, cells need to have a balanced supply of nucleotides, because A and T, as... 

It cannot be stressed too strongly that without exception, all known cellular life possesses an autocatalytic metabolism, even if the cells are het-erotrophic. Thus for the autocatalytic nature of the whole metabolic network it is not necessary to be able to identify a smaller autocatalytic core as the reductive citric acid cycle or the Calvin cycle. Imagine the following thought experiment. Take away all metabolites from a cell but leave all the water and the informational macromolecules in place. Can the network be recreated from the food materials only, or not Let us be generous and provide enough ATP also for the supposed kick-start. The fact is that no contemporary cell could resume its activity in this experiment. Consequently, all cells today possess a distributive autocatalytic network that cannot be seeded from outside, because some of its seed components cannot be taken up from medium. 

Synthetic polynucleotides and the genetic code. Informational Macromolecules, edited by H. J. Vogel, V. Bryson, and J. O. Lampen. New York Academic Press 1963. 

Joyce GF. Nonenzymatic template-directed synthesis of informational macromolecules. Cold Spring Harb. Symp. Quant. Biol. 1987 52 41-51. 

Pentoses are of prime importance for contemporary organisms as structural components of nucleic acids. The existence of the primordial RNA world, in which RNA is suggested to act as a catalyst as well as an informational macromolecule, assumes a large prebiotic source of ribose. Alternatively, the possible existence of pre-RNA molecules with backbones different from ribose phosphate has been considered [3]. 

Carcinogen Residues Bound Covalently to Informational Macromolecules Controlling Cell Replication... 

Solid Phase Organic Synthesis of Informational Macromolecules of Interest to Medicinal Chemists, 5... 

SOUD PHASE ORGANIC SYNTHESIS OF INFORMATIONAL MACROMOLECULES OF NTB EST TO MEDICINAL CHBVISTS... 

---