Macromolecule modification

A. Isolation and characterization of the resulting isoaspartyl and aspartyl derivatives, J. Biol. Chem. 268, 4745 751, 1993 Chen, J.S. and Mehta, K Tissue transglutaminase an enzyme with a spht personahty, Int. J. Bio-chem. Cell Biol 31, 817-836, 1999 Pickart, CM., Mechanisms underlying ubiquitination, Anna. Rev. Biochem. 70,502-533,2001 Pema, A.F., Capasso, R., Lombardi, C. et al., Hyperhomocysteinania and macromolecule modifications in uremic patients, Clin. Chem. Lab. Med. 43, 1032-1038, 2005. 

Oxidative damage of macromolecules (modification of NH2- and SH-groups of proteins, breaking of DNA chains, lipid peroxidation)... 

Besides the MDL Molfile formal, other file formats are often used in chemistry SMILES has already been mentioned in Section 2.3.3. Another one, the PDB file format, is primarily used for storing 3D structure information on biological macromolecules such as proteins and polynucleotides (Tutorial, Section 2.9.7) [52, 53). GIF (Crystallographic Information File) [54, 55] is also a 3D structure information file format with more than three incompatible file versions and is used in crystallography. GIF should not be confused with the Chiron Interchange Formal, which is also extended with. cif. In spectroscopy, JCAMP is apphed as a spectroscopic exchange file format [56]. Here, two modifications can be... 

Biomaterials with Low Thrombogenicity. Poly(ethylene oxide) exhibits extraordinary inertness toward most proteins and biological macromolecules. The polymer is therefore used in bulk and surface modification of biomaterials to develop antithrombogenic surfaces for blood contacting materials. Such modified surfaces result in reduced concentrations of ceU adhesion and protein adsorption when compared to the nonmodifted surfaces. 

PS has apolar characteristics and, thus, it is difficult to form a bond with metzils or polar materials. The adhesion capability of saturated polyhydrocarbons are dependent on the basis of polar properties of polymers [25]. Mitsu-aki and Masyasu [26] investigated the chemical modification of PS for anchoring of the carboxyl group to PS macromolecules with maleic anhydride (MA) in the presence of radiczil catalysis at 90-150°C. These authors... 

In the chemical modification of PS with MA, AA, EC, butadiene, and isoprene using cationic catalysis caused either destruction of macromolecules or the binding of functional groups to the aromatic ring. 

Benznidazole, a nitroimidazole derivative, has a mode of action that seems to involve covalent modification of macromolecules by nitroreduction intermediates. 

In the a modifications of i-PP, bilayers of macromolecules are stacked one on the top of the other in such a way that the top layer on one bilayer and the bottom layer of the bilayer in contact are made up of helices which are enantiomorphous. such helices are regularly anticlined for the ordered a2 modification, more or less at chance isoclined or anticlined for the disordered modifications. 

Protein macromolecules present in biological fluids are almost invariably heterogeneous in their characteristics. They may be products of more than one gene in the population (allotypes in the case of proteins isoenzymes in the case of enzymes), or a single individual (isotypes of proteins, allelozymes of enzymes), or be subject to post-translational modification. The result of this inherent molecular heterogeneity is that different forms of the same protein may behave differently with respect to... 

How do we decide whether to separate a mixture by gc or hplc In gc, mixtures are examined in the vapour phase, so that we have to be able to form a stable vapour from our mixture, or convert the substances in it to derivatives that are thermally stable. Only about 20% of chemical compounds are suitable for gc without some form of sample modification the remainder are thermally unstable or involatile. In addition, substances with highly polar or ionisable functional groups often show poor chromatographic behaviour by gc, being very prone to tailing. Thus hplc is the better technique for macromolecules, inorganic or other ionic species, labile natural products, pharmaceutical compounds and biochemicals. 

In a concurrently published report [160] Crooks and coworkers reported similar MUA-SAMs modified by covalent linking of hyperbranched macromolecules. These films containing a high density of surface carboxylic acid groups could selectively bind metal ions or undergo chemical modification. 

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