P-mercaptoethanol

Table 1 shows some biochemical properties of the pectolytic enzymes present in pool 1. The pectin lyase/pectate lyase activities (pool I) and polygalacturonase activity (pool II) were not significantly affected by NH4+, Na+ and K+ (0,25 - 2,5mM), while Al +, p-mercaptoethanol, Hg2+, EDTA, Ba + and Zn+2 (2,5mM) inhibited 30-100% these activities. On the other hand, Ca2+, Mg + and Mn + at 2,5mM concentration activated 20-100% pectin/pectate lyases but Ca " " and Cu " " (2,5mM) inhibited polygalacturonase activity about 42 - 70%. 

Tao, L., Thompson, J.T., Kennedy R.T. (1998). Optically-gated capillary electrophoresis of o-phthaldehyde/P-mercaptoethanol derivatives of amino acids for chemical monitoring. Anal. Chem. 70, 4015M022. 

Tissue surrogates heated in 6M guanidine HC1 supplemented with 0.5 M P-mercaptoethanol (BME), a disulfide-reducing agent, resulted in a protein... 

Immediately after irradiation, stop the reaction by the addition of 7 pi of 4 X SDS electrophoresis loading buffer or the equivalent (with a high concentration of reducing agent present) 0.2M Tris, 8 percent SDS, 2.88M P-mercaptoethanol, 40 percent glycerol, 0.4 percent xylene cyanol, 0.4 percent bromophenol blue. Heat the sample at 95°C for 5 minutes and analyze the complexes formed by electrophoresis. 

Sample preparation. All allantoic fluid of chicken embryos or calf serum used in experiments contained influenza virus (104—106 EID50/ml). The samples of biological fluids underwent photodynamic treatment as described above. One milliliter aliquots were taken before treatment and at 3 and 6 h after the start of experiment. To analyze the effect of photodynamic treatment on proteins we used alkaline denaturing electrophoresis in the presence of sodium dodecylsulfate (SDS) and P-mercaptoethanol (P-ME). 

The presence of permanent [Fe2S2] clusters in holo-NifU impeded spectroscopic characterization of transient clusters assembled in a NifS-mediated process. However, unambiguous evidence for NifS-directed assembly of oxidatively and reductively labile [Fe2S2] " clusters on NifU-1 was obtained using the combination of UV-visible absorption and resonance Raman spectroscopies (Yuvaniyama et al. 2000). The anaerobic reaction mixture involved NifU ferric ammonium citrate P-mercaptoethanol l-cysteine NifS in a 50 100 5000 1000 1 ratio. The presence of catalytic amounts of NifS facilitated meaningful UV-visible absorption results and monitoring the time course of cluster assembly. Although ferric ammonium citrate was used for these cluster assembly studies, control experiments... 

Serum-free medium AIM-V medium (Invitrogen, Carlsbad, CA), 20pM p-mercaptoethanol (Sigma-Aldrich). 

An analogous assay using a radiolabeled soft nucleophile would also be required to complement the hard nucleophile radiolabeled cyanide trapping assay. Investigations into radiolabeled glutathione have proved unsuccessful since the material is unstable due to cross-reactions induced by beta radiation. Alternate soft nucleophiles such as cysteine, N-acetyl cysteine and P-mercaptoethanol all have promise as radiolabeled substances for quantitative trapping experiments since they are more stable than GSH and equally nucleophilic, although clearly these would not be substrates for GST. 

Complete medium for culture of the undifferentiated ES-D3 embryonic stem cell line Dulbecco s Modified Eagle s Medium (DMEM), 20% Fetal bovine serum (FBS), 1% Nonessential Amino Acids (NEAA) (Gibco, Gaithersburg, MD), 2 mM L-Glutamine, 1% 5,000 lU/ml Penicillin/5,000 pg/ml Streptomycin, 0.1 mM P-Mercaptoethanol. 

In a well-ventilated hood, add 10 mL of p-mercaptoethanol to the gel suspension with constant stirring, and continue for 24 h at room temperature (see Note 24)... 

Figure 2.41 Denaturing and self-reassembly of ribonuclease. The correct folding occurs only when disulfide bond formation is made reversible by the addition of P-mercaptoethanol (RSH) allowing the system to equilibrate (Reproduced from Section Key Reference by permission of The Royal Society of Chemistry).

Although DTT is not necessary in the enzymatic conversion of penicillin G [14], this compound is known to stimulate the expandase activity of frozen crude extracts of S. clavuligerus and C. acremonium on penicillin N [40], However, neither this reagent nor P-mercaptoethanol was able to stimulate the subsequent reaction with penicillin G when added during preincubation with FeS04 and ascorbate [43],... 

Despite the assertion over a number of years that vanadate is rapidly reduced in the presence of ligands such as p-mercaptoethanol and dithiothreitol, it is now known that this assertion is subject to qualification. Solution studies have shown that the vanadium(V) complexes of p-mercaptoethanol [36] and dithiothreitol [37] can be quite stable in solution. At pH 7.1, reduction of vanadium in the dithiothreitol complex occurs in a timescale of about 90 min, and even at pH 6.2, significant production of V(IV) is not observed for about 20 min. When the crystalline vana-dium(V) complex of p-mercaptoethanol was dissolved in water, it was shown to... 

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