Mutation characterization

Mutations in rhodopsin and other photoreceptor proteins are linked to retinitis pigmentosa. Retinitis pigmentosa (RP) is a group of inherited retinopathies that affects about 1 in 4,000 humans [26], RP maybe classified into four types autosomal dominant (19%), autosomal recessive (19%),X-linked (8%) and allied diseases (54%). RP is characterized by loss of night vision in the early stage, followed by loss of peripheral vision. Chromosomal loci for numerous RP genes have been mapped and mutations characterized [27]. 

Gene mapping detection of heteromorphisms and determination of parental origin of heteromorphisms Detection of gene mutations Characterization of structural aberrations Identification of marker chromosomes Characterization of tumor cells Chromosome and karyotype evolution Spatial topography of chromosomes... 

Scanning Is Helpful for Large Gene Mutation Characterization. 209... 

Table 8.6 lists the mass differences due to the substitutions of a given amino acid by another in the sequence of a peptide chain [101]. The accuracy of the molecular mass determination is critical for the success of the mutation characterization. The required accuracy depends not only on the determined molecular mass, but also on the detected substitution. Indeed, the characterization of Gln/Lys substitution needs less accurate mass measurement with a 1 kDa peptide than with a 40kDa protein. In the same way, the characterization of Gly/Trp substitution is easier than the characterization of Gln/Lys substitution. 

Mullberg, J., Oberthur, W, Lottspeich, F., Mehl, E. Dittrich, E., Graeve, L., Heinrich, P C., and Rose-John, S. (1994). The soluble human IL-6 receptor. Mutational characterization of the proteolytic cleavage site. J Immunol. 752 4958-4968. 

Mutations caused by substances with biogenetic effects may be divided into gene (point) mutations characterized by small changes of DNA (only one pair or at most several nucleotides are hit) and chromosomal mutations, visible under a conventional microscope (e.g. chromosome breaks, deletions, translocations, etc.). Depending on the mechanism of the effects of genotoxic substances, the mutation can result from (1) the substitution of analogues of bases, (2) the chemical conversion of DNA and of its nucleotides, (3) binding of chemical substances to DNA and (4) DNA depolymerization [3]. 

Zeeb, M., and Balbach, J. Single-stranded DNA binding of the cold-shock protein CspB from Bacillus subtilis NMR mapping and mutational characterization. J. Protein Sci. 12, 112-123 (2003). 

It should be noticed that the group of mutations characterized by the loss in ability for either band to form a puff is small. 

As these experiments with engineered mutants of trypsin prove, we still have far too little knowledge of the functional effects of single point mutations to be able to make accurate and comprehensive predictions of the properties of a point-mutant enzyme, even in the case of such well-characterized enzymes as the serine proteinases. Predictions of the properties of mutations using computer modeling are not infallible. Once produced, the mutant enzymes often exhibit properties that are entirely surprising, but they may be correspondingly informative. 

Garrett, R. M., et al., 1998. Human snlfite oxidase R160Q Identification of the mutation in a snlfite oxidase-deficient patient and expression and characterization of the mutant enzyme. Proceedings of the National Academy of Sciences HSA 95 6394—6398. 

Over 4 decades, between 1960 and 2000, the development of new antibiotics used well characterized basic structures for partial synthetic modifications, primarily to overcome resistance by increasing the pharmacodynamic properties and, secondarily, to improve the pharmacokinetic profile of older compounds. However, bacteria rapidly responded by acquiring additional genetic alterations either as mutations or by accumulating resistance genes as part of mobile genetic elements ( integrons) on transferable resistance plasmids. 

Disorder characterized by atrophy ofthe choroid (the thin membrane covering most of the posterior of the eye between the retina and sclera) and degeneration of the retinal pigment epithelium resulting in night blindness. The disease is caused by mutations in Rab escort protein Repl (component A of Rab geranylgeranyl transferase). 

Disorder characterized by an inability to concentrate urine in response to vasopressin due to mutations in the vasopressin V2 receptor gene or the AQP2 gene. 

Several diseases involving dysregulation of MR function have been described although most of them are not causatively linked to the receptor itself. Pseudohypoaldosteronism for example is a syndrome of mineralocorticoid resistance characterized by urinary salt loss and dehydration. However, only very rarely mutations in the MR gene have been found in these patients so far. In most cases, this syndrome appears to be linked to defects in the subunits of the amiloride-sensitive sodium channel ENaC, a major target of mineralocorticoid action in the kidney. 

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