Mutation quantitative

In Figure 7b, the data are plotted as AG yielding a linear function. Extrapolation to 2ero denaturant provides a quantitative estimate of the intrinsic stability of the protein, AG, which in principle is the free energy of unfolding for the protein in the absence of denaturant. Comparison of the AG values between mutant and wild-type proteins provides a quantitative means of assessing the effects of point mutations on the stability of a protein. 

Lohman PHM. 1999. Qualitative and quantitative procedures for health risk assessment. Mutat Res 428 237-254. 

Waters MD, Stack HF, Jackson MA, et al. 1994. The performance of short-term tests in identifying potential germ cell mutagens A qualitative and quantitative analysis. Mutat Res 341 109-131. 

Carbonic anhydrase (CA) exists in three known soluble forms in humans. All three isozymes (CA I, CA II, and CA III) are monomeric, zinc metalloenzymes with a molecular weight of approximately 29,000. The enzymes catalyze the reaction for the reversible hydration of C02. The CA I deficiency is known to cause renal tubular acidosis and nerve deafness. Deficiency of CA II produces osteopetrosis, renal tubular acidosis, and cerebral calcification. More than 40 CA II-defi-cient patients with a wide variety of ethnic origins have been reported. Both syndromes are autosomal recessive disorders. Enzymatic confirmation can be made by quantitating the CA I and CA II levels in red blood cells. Normally, CA I and CAII each contribute about 50% of the total activity, and the CAI activity is completely abolished by the addition of sodium iodide in the assay system (S22). The cDNA and genomic DNA for human CA I and II have been isolated and sequenced (B34, M33, V9). Structural gene mutations, such as missense mutation, nonsense... 

Daugherty, P.S., Chen, G., Iverson, B.L. and Georgiou, G. (2000) Quantitative analysis of the effect of the mutation frequency on the affinity maturation of single chainFv antibodies. Proceedings of the National Academy of Sciences of the United States of America, 97, 2029-2034. 

TfR is low in these patients, PIT is normal and most iron is stored in hepatocytes. In patients with hypoplastic anaemias and with transfusion iron overload, the BM cannot utilize iron, resulting in low TfR expression and decreased iron absorption. Quantitative analysis of all iron fluxes, which can be deduced from Figure 9.1, can assist in understanding the clinical expression of mutations of proteins involved in iron transport. 

Novicik, A. and Szilard, L. (1951). Genetic mechanisms in bacteria and bacterial viruses. I. Experiments on spontaneous and chemically induced mutations of bacteria growing in the chemostat. Cold Spring Harbor Symposia on Quantitative Biology 16 337-343. 

Recently, Sage and Haseltine (49) have quantitatively determined the spectrum of DNA lesions induced by reactions of BPDE with DNA. They found that alkali-labile lesions account for about 40% of the DNA adducts. There was a striking correlation between the mutation frequencies induced by BPDE in lacl and the frequencies of alkali sensitive lesions at G, A, and C residues. Apurinic/apyrimidinic sites are common alkali-sensitive lesions. Earlier work by Drink-water e al. (48) had also shown that treatment of DNA with BPDE generated apurinic/apyrimidinic sites. 

Crebelli, R., Andreoli, C., Carere, A., Conti, G., Conti, L., Cotta-Ramusino, M., Benigni, R. The induction of mitotic chromosome malsegregation in Aspergillus nidulans. Quantitative structure activity relationship (QSAR) analysis with chlorinated aliphatic hydrocarbons. Mutat. Res. 1992, 266, 117-134. 

Chinese Hamster CHO/Hgprt System. Chinese hamster ovary (CHO) cells have 21 or 22 chromosomes with one intact X chromosome and a large acrocentric marker chromosome (Natarajan and Obe, 1982). The use of these cells in mammalian mutation experiments was first reported by Hsie et al. (1975), and was refined into a quantitative assay for mutagenicity testing by O Neill. The performance of this system has been reviewed by the USA EPA Gene-Tox Program. The experimental procedure for this assay is similar to the V79/Hgprt system already described, and for more detailed descriptions the reader is referred to Li et al. (1987). 

Barber ED, Donish WH, Mueller KR. 1981. A procedure for the quantitative measurement of the mutagenicity of volatile liquids in the Ames Salmonella/microsome assay. Mutat Res. 90 31-48. 

Quantitative PCR has been widely used to determine the amount (number of molecules) of DNA molecules in a test sample. The best quantitative PCR method involves the addition of known amounts of a similar DNA or RNA fragment, such as one containing a short deletion or specific mutation, to the test sample before amplification. Such internal standards must be precisely calibrated to ensure that they are amplified and detected in a form and manner that are similar to the test sample. The ratio of the internal standard and the targeted template will depend on the amount of internal standard added and allows for the determination of the amount of the targeted molecule in the test sample. Therefore, the ideal standard for quantitative amplification based assays should have a structure that is comparable to the template of interest and which allows for the simultaneous amplification of both template and standard using a single primer pair. 

Denissenko, M.F. et al., Quantitation and mapping of aflatoxin DNA damage in genomic DNA using aflatoxin Bi-8,9-epoxide and microsomal activation systems, Mutat. Res., 425, 205, 1999. 

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