Sulfhydryl reagents

Hudson EN, Weber G (1973) Synthesis and characterization of two fluorescent sulfhydryl reagents. Biochemistry 12 4154—4161... 

DNA polymerases from several different animal cells have been isolated and studied. The three DNA polymerases of animal cells, called a, p, and y, can be distinguished by their molecular weights, template specificity, and sensitivity to sulfhydryl reagents. Table 14.3 compares the three in regard to these differences. DNA polymerase a is probably the most important for DNA replication. This enzyme shares many functional properties with DNA polymerase III of E. coli ... 

Inhibition by sulfhydryl reagents Sensitive Less sensitive Sensitive... 

Haugaard, N., Cutler, J., and Ruggieri, M.R. (1981) Use of N-ethylmaleimide to prevent interference by sulfhydryl reagents with the glucose oxidase assay for glucose. Anal. Biochem. 116, 341-343. 

Zahn, H., and Lumper, L. (1968) Specificity of bifunctional sulfhydryl reagents and synthesis of a defined dimer of bovine serum albumin. Hoppe-Seyler s Z. Physiol. Chem. 349, 485. 

If this idea is correct, it should be possible to selectively perturb one of the two fluxes mediated by the glutamate transporters. Indeed, analysis of a mutant with a cysteine residue introduced in the hydrophobic linker region, 1421C (corresponding to position 451 in GLT-1, see Fig. 4) reveals that the coupled uptake in this mutant is very sensitive to sulfhydryl reagents (54). Strikingly, the substrate-induced anion conductance is not affected at all by the sulfhydryl reagents (54). Similar observations have... 

Golovanevsky, V. and Kanner, B. I. (1999) The reactivity of the gamma-aminobutyric acid transporter GAT-1 toward sulfhydryl reagents is conformationally sensitive. Identification of a major target residue. J. Biol. Chem. 274,23020-23026. 

Cysteine mutations in GAT verified an intracellular position for Cys3998.63 in the fourth intracellular loop (IL4) between TM8 and TM9 (17), and an extracellular location for positions 73i.55-76i.58 in ELI (15), as cysteines at these positions conferred sensitivity to the sulfhydryl reagents, MTSEA and A-ethylmaleimide (for Cys39 98.63) and MTSET (residues 73i.55-76i.58). 

Seal RP, Leighton BH, Amara SG. 1998. Transmembrane topology mapping using biotin-containing sulfhydryl reagents. Methods Enzymol 296 318-331. 

The effects of various compounds and inhibitors on the enzyme activity were tested. The activity was measured in the presence of 1 -10 mM of various metal ions and compounds. The enzyme activity was inhibited by sulfhydryl reagents (concentration 1 mM) such as PbCl2 (relative activity, 18%), SnCl2 (17%),HgCl2... 

Mudd, J. B.. T. T. McManus, A. Ongun, and T. E. McCullough. Inhibition of glycolipid biosynthesis in chloroplasts by ozone and sulfhydryl reagents. Plant Physiol. 48 335-339, 1971. 

Figure 11. The uptake of O3 by a. sulfhydryl reagent. A. Semilogarithmic kinetic plot of O3 uptake by Dithio-threitol (DTT). The ozone uptake was calculated as described in Figure 8. Numbers at the side of the graph refer to final concentrations of added DTT. Different symbols represent different experiments. B. Log-dog plot of rate constant and total O3 taken up with DTT concentrations. The rate constant (K) of O3 uptake and total (O3) were calculated from Part A.

In contrast to the AChR, AChE does not bind bungarotoxin or sulfhydryl reagents. It is inhibited by excess substrate (3 x I0 M), and the of electric eel AChE is about 10 M. The specific activity of the enzyme is one of the highest known 750 nmol/mg-hr, with a turnover time of 30-60 msec and a turnover number of 2-3 x 106. It is therefore one of the most efficient and fastest enzymes known. 

Schirmer, R.H. Thuma, E. Sensitivity of adenylate kinase isozymes from normal and dystrophic human muscle to sulfhydryl reagents. Biochim. Biophys. Acta, 268, 92-97 (1972)... 

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