Biomacromolecules functional properties

Lahaye, M. and Robic, A. (2007). Structure and functional properties of ulvan, a polysaccharide from green seaweeds. Biomacromolecules 8(6), 1765-1774. 

Strand, SP Issa, MM Christensen, BE Varum, KM Artursson, P. Tailoring of Chltosans for Gene Delivery Novel Self- Branched Glycosylated Chitosan Oligomers with Improved Functional Properties. Biomacromolecules, 9 (11), 2008, 3268-3276. 

Are biomacromolecules of greater mass than that of rubredoxin (6 kDa), in particular enzymes (typically, >50 kDa), capable of such rapid conformational adjustment with decreasing temperature At present the answer appears to be We do not know. Unfortunately, the reduction potentials) of enzymes in solution is not usually determinable with direct electrochemistry, so you are invited to find and explore other molecular properties to probe as a function of temperature, for example, (de) protonations near paramagnetic sites that can be followed both by optical and by EPR spectroscopy. 

Adsorbents for biomacromolecules such as proteins have special properties. First, they need to have large pore sizes. A ratio of pore radius to molecule radius larger than 5 is desirable to prevent excessive diffusional hindrance (see Intraparticle Mass Transfer in this section). Thus, for typical proteins, pore radii need to be in excess of 10-15 nm. Second, functional groups for interactions with the protein are usually attached to the adsorbent backbone via a spacer arm to provide accessibility. Third, adsorbents based on hydrophilic structures are preferred to limit nonspecific interactions with the adsorbent backbone and prevent global unfolding or denaturation of the protein. Thus, if hydrophobic supports are used, their surfaces are usually rendered hydrophilic by incorporating hydrophilic coatings such as dextran or polyvinyl alcohol. Finally, materials stable in sodium hydroxide solutions (used for clean-in-place) are... 

In conclusion, biomacromolecules have evolved to be big because from their size and structural variety arise a number of emergent properties that allow them not only to function with utmost efficiency, but to do so in a manner fully controlled by the higher levels of complexity characteristic of living systems (see Section 2.4). 

It is beyond the scope of this book to go into further details of comparing structural organization in synthetic and biological macromolecules. We cannot resist noting however, that one may consider as the ultimate goal of polymer materials chemistry to synthesize exact and accurate structures of the appropriate monomers in well-defined systems to achieve required functions. Differences in properties and function between man-made polymer parts and biomaterials made up of natural biomacromolecules may well be related to differences in their primary structure and architectural control. Proteins and nucleic acids are precisely defined in their... 

Not all levels of structure are required or represented in all biomacromolecules. In general, all biomacromolecules require a level of structure up to and including second-ary/tertiary for biological function. It should be emphasized that a representation/visuali-zation of a molecule is only a model described by the atoms and the positions (coordinates) of the atoms in three-dimensional space. This model is correct only when it conforms to the experimentally observed properties and activities. 

Molecules are dynamic, undergoing vibrations and rotations continually. Therefore the static picture of molecular structure provided by MM is not realistic. Flexibility and motion are clearly important to the biological functioning of biomacromolecules. These molecules are not static structures, but exhibit a variety of complex motions both in solution and in the crystalline state. Energy minimization concerns only the potential energy term of the total energy and so it treats the biomacromolecule as a static entity. The dynamic properties of the atoms in a macromolecule or the momentum of the atoms in space requires the description of the kinetic term. The momentum (p) is related to the force exerted on the atom (Ft) and the potential energy (V) by... 

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