Biopolymer chains

The ionic strength dependence of intrinsic viscosity is function of molecular structure and protein folding, ft is well known that the conformational and rheological properties of charged biopolymer solutions are dependent not only upon electrostatic interactions between macromolecules but also upon interactions between biopolymer chains and mobile ions. Due electrostatic interactions the specific viscosity of extremely dilute solutions seems to increase infinitely with decreasing ionic concentration. Variations of the intrinsic viscosity of a charged polyampholite with ionic strength have problems of characterization. 

Tbe answer to the question of the aetiology of macromolecular sequences is elusive as is the emergence of homochirality in the biopolymer chains. Have chains emerged when on Earth there was already an established homochirality of the biomonomers, or was the formation of long chains the cause of the emergence of homochirality ... 

Extended Arrangements of Peptides and Proteins. Amino acids are finked from the carboxyl to the amine with formation of an amide bond, often referred to as the peptide fink. The repeating (— N—C — CO—) unit is called the peptide or protein backbone. Peptides and proteins differ only in the number of amino acids present in the biopolymer chain. The cutoff is arbitrarily set. Often, but not always, a peptide is designated as having fewer than 100 amino acids and the protein possesses more. Backbone amide groups have been found to play a role in enzyme catalysis. 

Figure 5.1. Notation for torsion angles of biopolymer chains. Torsion angles ( and ift) that affect the main chain conformations of biopolymers are shown for polysaccharide (a), polypeptide (b), and polynucleotide (c) chains according to the IUBMB notation. The two torsion angles, and ij>, specified around the phosphodiesteric bonds of nucleic acids correspond to a and respectively. Reproduced from IUBMB at http //www.chem.gmw. ac.uk/iubmb.

The radiation-induced conductivity in hydrated samples of aligned versus non-aligned solid DNA fibers was compared by Warman et al. [166]. The dry fibers were found to be essentially nonconducting, as a water content of 10-15 waters per base pair is necessary to observe conductivity. Under these conditions, the conductivity of the aligned and nonaligned films was found to be similar. It was concluded that conductivity in solid B-DNA is due to highly mobile charge carriers within the outer mantle of the biopolymer chains rather than within the base-pair cores. ... 

The hnal product may be damaged, if drastic conditions are reqnired to cleave the biopolymer chain from the polymer. 

Sequencing of individual fragments The sequencing can begin at one of the termini in a terminal sequencing experiment or can be conducted within the biopolymer chain in an internal sequencing experiment. 

Colvin, J. T Stapleton, H. J. Fractal and spectral dimensions of biopolymer chains solvent studies of electron spin relaxation rates in myoglobin azide. J. Chem. Phys. 1985, 82(10), 4699 706. 

The driving force for the molecular assembly of polymeric molecules into ID fiberlike objects stems from a fine balance between the entropic cost of forming ordered supramolecular structures with reduced flexibihty and the enthalpic gain resulting from intermolecular interactions [8]. Inter- and intrachain hydrogen bonding is by far the most important driving force for the association of biopolymer chains and the stabilization of fibrils in aqueous media. 

Rakovic, D., Dugic, M and Plavsic, M., Biopolymer chain folding and biomolecular recognition a quantum decoherence theory approach. Material Science Forum, 494, 513-518, 2005. 

---