Structural and functional consequences

Gillis, J.M., 1999, Understanding dystrophinopathies an inventory of the structural and functional consequences of the absence of dystrophin in muscles of the mdx mouse, J Muscle Res Cell Motil, 20, pp 605-625. 

In this era of proliferating reviews, investigators have many opportunities to satisfy such urges, particularly in a field such as membrane protein structure and function. Consequently, I would particularly like to thank the authors of this volume for the time commitment and effort required to prepare their contributions. 

Murad K L, Mahany K L, Kuypers F A, et al. (1999). Structural and functional consequences of antigenic modulation of red blood cells with methoxypoly(ethylene glycol). Blood 93 2121-2127. 

A major area for new research concerns the structural and functional consequences of adsorption of proteins to surfaces (items 3-5 in Table IV). Measurement of conformational change is still in an early stage of development. Most methods for studying adsorbed protein conformation are restricted to comparison of spectral differences induced by adsorption, without knowledge of the actual type or amount of change these differences reflect. Better methodology, especially on quantitative aspects, is sorely needed in this area. The orientation of adsorbed proteins may prove to be readily explored with the monoclonal antibody method and therefore certainly deserves wider application. Finally, the behavior of enzymes and antibodies at interfaces is not... 

Staphylococcal nuclease, a DNA-hydrolyzing enzyme, is a single polypeptide chain of 149 amino acid residues it has no disulfide bridge and contains one Ca ion. This protein was originally isolated from Staphylococcus aureus, but the gene has been cloned and inserted into several expression systems. Various mutants of this enzyme have been used to generate biochemical and biophysical data on the structural and functional consequences of altering the protein amino acid sequence. 

R 543 M.J. Woods, J.H. Prieto and E.A. Komives, Structural and Functional Consequences of Methionine Oxidation in Thrombomodulin , Biochim.Biophys.Acta, 2005,1703,141... 

The structural and functional consequences of the Arg — Cys substitution are less clear. This mutation results in both defective assembly and complement fixation by MBP. Mutagenesis studies indicate that the presence of the cysteine residue is responsible for both the altered oligomeric composition and the decreased complement fixation activity [51], One possibility is that the cysteine residue forms disulfide bonds or is modified during synthesis, preventing correct assembly of the oligomeric forms. 

In most cases, biological activity of proteins is dependent on specific three-dimensional (3D) tertiary strucmres. Not surprisingly, as a consequence of this interest in protein structure and function. 

Acetylcholinesterase is a component of the postsynaptic membrane of cholinergic synapses of the nervous system in both vertebrates and invertebrates. Its structure and function has been described in Chapter 10, Section 10.2.4. Its essential role in the postsynaptic membrane is hydrolysis of the neurotransmitter acetylcholine in order to terminate the stimulation of nicotinic and muscarinic receptors (Figure 16.2). Thus, inhibitors of the enzyme cause a buildup of acetylcholine in the synaptic cleft and consequent overstimulation of the receptors, leading to depolarization of the postsynaptic membrane and synaptic block. 

Certain organotins, such as di- -octyltin dichloride (DOTC) and tributyltin oxide (TBTO), alter the structure and function of the thymus and consequently affect pri-... 

The small subunit is composed of two domains. The N-terminal domain shows the characteristic architecture of flavodoxin with the phosphate moiety of the flavin cofactor occupying the binding pocket of the proximal [4Fe-4S] cluster. This N-terminal domain, including the proximal cluster, is found in all [NiFe] hydrogenases and is consequently an essential feature, both structural and functional, of these enzymes. By contrast, the C-terminal domain that binds the other [FeS] clusters is less organised and more variable in [FeS] cluster content and amino acid sequence. 

The nucleosome core particle is a relatively stable and homogenous structure that is easily prepared, and as such has formed the basis for numerous studies into chromatin structure and function. However, several recent studies have suggested that what is true for the nucleosome core may not always be true for nucleosome arrays, nor even for nucleosomes containing linker DNA. For example, the core histone tails preferentially interact with linker DNA when is it present, whereas they are constrained to bind intranucleosomal DNA in core particles [46 8]. Consequently, the activities of proteins that require access to the tails or the DNA may be affected, and it has been shown that both DNA ligase and P/CAF are less active on nucleosome core particles than other chromatin substrates [49,50]. Similar concerns apply to the interaction of HMGN proteins with nucleosome core particles, and results from studies of these complexes must be considered in the wider context of how these proteins may interact with nucleosome arrays. 

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