[103] Preparation and assay of deoxyribonucleic acid from animal tissue

Zamenhof, Stephen

doi:10.1016/s0076-6879(57)03446-1

Cited by 417 publications

(139 citation statements)

References 17 publications

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“…Iron content was determined by plasma emission spectroscopy using the Jarrel-Ash model 750 Atomcomp. The modified Biuret method developed by Zamenhof and Chargoff [9] was used for the protein determination using horse cytochrome c as the standard. Amino acid analyzes were performed with a Beckman model 120 amino acid analyzer.…”

Section: Methodsmentioning

confidence: 99%

Spectroscopic characterization of a high‐potential monohaem cytochrome from Wolinella succinogenes, a nitrate‐respiring organism

Gordeladze¹,

Sletholt²,

Thorn³

et al. 1988

European Journal of Biochemistry

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When purified, a high-potential c-type monohaem cytochrome from the nitrate-respiring organism, Wollinellu succinogenes (VPI 10659), displayed a minimum molecular mass of 8.2 kDa and 0.9 mol iron and 0.95 mol haem groups/mol protein. Visible light spectroscopy suggested the presence of an equilibrium between two ligand arrangements around the haem, i. e. an absorption band at 695 nm characteristic of haem-methionine coordination (low-spin form) coexisting with a high-spin form revealed by a band at 619 nm and a shoulder at 498 nm. The mid-point redox potential measured by visible redox titration of the low-spin form was approximately + 100 mV.Binding cyanide ( K , = 5 x lo5 M-') resulted in the displacement of the methionyl axial residue, and full conversion to a low-spin, cyanide-bound form.Structural features were studied by 300-MHz 'H-NMR spectroscopy. In the oxidized state, the pH dependence of the haein methyl resonances (pH range 5 -10) and the magnetic susceptibility measurements (using an NMR method) were consistent with the visible light spectroscopic data for the presence of a high-spin/low-spin equilibrium with a transition pK, of 7.3. The spin equilibrium was fast on the NMR time scale. The haem methyl resonances presented large downfield chemical shifts. An unusually broad methyl resonance at around 35 ppm (pH = 7.5, 25°C) was extremely temperature-dependent [6(323K) -6(273K) = 7.2 ppm] and was assigned to the S-CH3 group of the axial methionine. In the ferrous state only a low-spin form is present. The haem meso protons, the methyl group and the methylene protons from the axial methionine were identified in the reduced form. The resonances from the aromatic residues (three tyrosines and one phenylalanine) were also assigned.Detailed monitoring of the NMR-redox pattern of the monohaem cytochrome from the fully reduced up to the fully oxidized state revealed that the rate of the intermolecular electronic exchange process was approximately 6 x lo6 M-' sK1 at 303 K and pH = 6.31.A dihaem cytochrome also present in the crude cell extract and purified to a homogeneous state, exhibited a molecular mass of 21 kDa and contained 2.43 mol iron and 1.89 mol haem c moieties/mol cytochrome. The absorption spectrum in the visible region exhibited no band at 695 nm, suggesting that methione is not a ligand for either of the two haems. Recovery of only small amounts of this protein prevented more detailed structural analyzes

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Section: Methodsmentioning

confidence: 99%

Spectroscopic characterization of a high‐potential monohaem cytochrome from Wolinella succinogenes, a nitrate‐respiring organism

Gordeladze¹,

Sletholt²,

Thorn³

et al. 1988

European Journal of Biochemistry

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“…Protein was determined by the modified micro-biuret method (Zamenhof, 1957) with crystalline serum albumin as a standard. The measurements were performed in a Zeiss spectrophotometer Model PMQ 11.…”

Section: Methodsmentioning

confidence: 99%

Alkaline Phosphatase in Dictyostelium discoideum

Gezelius

Wright

1965

Journal of General Microbiology

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SUMMARYSeveral phosphatases have been demonstrated in Dictyostelium discoideum. The alkaline phosphatase, pH optimum 9.0, is a 5'-nucleotidase, attacking adenosine monophosphate and deoxyadenosine monophosphate, but catalyses also hydrolysis of p-nitrophenyl phosphate. In the absence of exogenous nutrients this enzyme increases about 6-fold in vitro during differentiation. Its activity\in vivo may in part be controlled through endproduct inhibition by orthophosphate which has been found to accumulate in the cells during sporulation. Exogenous orthophosphate and glucose repress the levels of alkaline phosphatase in the spores. The data support the conclusion that end product inhibition and repression collaborate to ensure maximal alkaline phosphatase activity in vivo during culmination. Exogenous adenosine and deoxyadenosine increase the alkaline phosphatase levels in the sorocarps.

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“…Briefly, the cells were harvested and washed, and soluble proteins were obtained by disruption with glass beads and centrifugation, using the supernatant as crude extract. ONPG was used as a substrate and specific activities were assessed from its conversion at 30 • C, with protein concentrations determined by the microbiuret method (Zamenhoff, 1957), using bovine serum albumin as a standard.…”

Section: β-Galactosidase Determinations and Multiwell Analysesmentioning

confidence: 99%

The effect of tea tree oil and antifungal agents on a reporter for yeast cell integrity signalling

Straede

Corran

Bundy

et al. 2007

Yeast

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Cell integrity in Saccharomyces cerevisiae is ensured by a rigid cell wall whose synthesis is controlled by a highly conserved MAP kinase signal transduction cascade. Stress at the cell surface is detected by a set of sensors and ultimately transmitted through this cascade to the transcription factor Rlm1, which governs expression of many genes encoding enzymes of cell wall biosynthesis. We here report on a number of versatile reporter constructs which link activation of a hybrid, Rlm1-lexA, by the MAP kinase Mpk1/Slt2 to the expression of the bacterial lacZ gene. This system was adapted to automated microwell screening and shown to be activated by a number of compounds inhibiting cell wall biosynthesis or interfering with plasma membrane function. In addition, we tested tea tree oil and two of its purified constituents (α-terpineol, terpinen-4-ol) for their effects on growth and on cell integrity signalling using such reporter strains. Tea tree oil was found to inhibit growth of wild-type and slg1/wsc1 mutant cells at a threshold of approximately 0.1% v/v, with the purified compounds acting already at half these concentrations. A mid2 deletion displayed hyper-resistance. Tea tree oil also induces the signalling pathway in a dose-dependent manner.

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[103] Preparation and assay of deoxyribonucleic acid from animal tissue

Cited by 417 publications

References 17 publications

Spectroscopic characterization of a high‐potential monohaem cytochrome from Wolinella succinogenes, a nitrate‐respiring organism

Spectroscopic characterization of a high‐potential monohaem cytochrome from Wolinella succinogenes, a nitrate‐respiring organism

Alkaline Phosphatase in Dictyostelium discoideum

The effect of tea tree oil and antifungal agents on a reporter for yeast cell integrity signalling

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