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Biomedical subjects

P D Dean

Publications and source records attributed to P D Dean.

At least 37 records · Page 2Linked to original sources
PubMed1979

Protein purification using immobilised triazine dyes.

This review attempts to identify proteins which selectively interact with immobilised triazine dyes such as Cibacron blue F3GA and Procion red HE 3B. Different support matrices are compared by examining the capacities of these dyes for proteins. Various approaches to the immobilisation of triazine dyes are considered together with the use of spacers. Some theories of the mechanism of protein retardation by immobilised dyes are discussed. A number of methods are suggested for the measurement of dye concentrations and for the modification of the binding of proteins to dye columns. The variety of elution methods is compared with a view to optimizing purifications. The scope of applications is reviewed as well as the choice of dye. Some advantages of triazine dyes over other affinity ligands are given. It is concluded that although no satisfactory mechanism for the binding of triazine dyes to proteins has yet been proposed, these dyes possess considerable potential for protein purification, particularly when applied on the large scale.

Animals↗
PubMed1979

Plasma equilin concentrations in an oophorectomized woman following ingestion of conjugated equine oestrogens (Premarin).

The plasma equilin concentration was 25.2 nmol/l (6.7 ng/ml) 4 h after an oral dose of Premarin (1.25 mg), and a maximum concentration of 20.5 nmol/l (5.5 ng/ml) was recorded 3 h after a smaller dose (0.625 mg) was given. 24 h later, the plasma equilin was still considerable, being 6.1 nmol/l (1.6 ng/ml) and 3.7 nmol/l (1.2 ng/ml) for the larger and smaller dosages respectively. The findings for equilin are considerably higher than physiological oestrogen concentrations and in addition show that daily therapy with Premarin could lead to cumulation of the steroid.

17-Ketosteroids↗
PubMed1978

The selective retardation of NADP+-dependent dehydrogenases by immobilized procion red HE-3B.

The capacities of Procion Red HE-3B and Cibacron Blue F3G-A immobilized to Sepharose CL-4B and Matrex 201R for NAD+-, NADP+- and NAD(P)+-dependent dehydrogenases were measured. Procion Red HE-3B columns retarded NADP+-dependent dehydrogenases more effectively than NAD+-dependent dehydrogenases, whilst immobilized Cibacron Blue F3G-A retarded NAD+-dependent dehydrogenases more effectively than NADP+-dependent dehydrogenases. The capacity of procion Red HE-3B-Sepharose CL-4B for five dehydrogenases was highest in the region of 70nmol of immobilized ligand/ml of settled gel. The effects of using poly(ethyleneimine) as a spacer for both porous and pellicular supports were also examined. Four NADP+-dependent dehydrogenases were purified from yeast extract by using Procion Red HE-3B-Sepharose CL-4B. Two NAD+-dependent dehydrogenases were purified from the same source using Cibacron Blue F3G-A-Sepharose CL-4B. These results are discussed in relation to the use of immobilized Procion Red HE-3B to purify dehydrogenases. This immobilized dye's chromatograhic behaviour is compared with that of immobilized nucleotides. The most important feature of immobilized tirazine dyes seems to be their high operational capacities when compared with group-specific nucleotide adsorbents.

Chromatography, Affinity↗
PubMed1978

Affinity adsorbents consisting of nucleic acids immobilized via bisoxirane activated polysaccharides.

An easy and efficient procedure for the immobilization of polynucleotide ligands to bisoxirane activated insoluble polysaccharides has been elaborated and is described in this paper. The resulting materials have been applied to the chromatography of DNA polymerase I, and RNA polymerase from E.coli. Because of their extraordinary stability to temperature, formamide, and alkaline conditions they seem to be particularly useful adsorbents for nucleic acid hybridization.

Chemical Phenomena↗
PubMed1977

The effect of matrix on the binding of albumin to immobilized Cibacron Blue.

With Cibacron Blue as a ligand, the suitability of Sepharose, Sephacryl, cellulose and Ultrogel as column supports for the affinity chromatography of human serum albumin was examined. Sepharose and Sephacryl were the most effective matrices. Albumin was readily removed from such columns by using an electrophoretic desorption technique.

Chromatography, Affinity↗
PubMed1977

A specific direct radioimmunoassay for oestriol-16alpha-glucuronide in pregnancy plasma.

A specific radioimmunoassay has been developed for measuring oestriol-16alpha glucuronide in pregnancy plasma using a highly specific antiserum. The specificity of this antiserum has been assessed by the 50% displacement method and by measuring oestriol-16alpha-glucuronide concentrations in pregnancy plasma samples, both with and without chromatography. The antiserum was found to have Ka of 1.3 X 10(10) M-1. The assay had a sensitivity of 5 pg (least quantity of oestriol-16alpha-glucuronide distinguishable from the zero point, p less than 0.05), an intra-assay variation of 6.07% and an inter-assay variation of 3.36%. The assay was used to measure plasma oestriol-16alpha-glucuronide concentrations throughout eight pregnancies, five of which were normal and three had some defined abnormality.

Cross Reactions↗
PubMed1977

An examination of potential matrices for the affinity chromatography of NADP+-linked dehydrogenases with special reference to 6-phosphogluconate dehydrogenase.

1. 6-phosphogluconate dehydrogenase from sheep liver has been purified 350-fold by affinity chromatography with a final specific activity of 18 micronmol of NADP+/reduced min per mg of protein and an overall yield of greater than 40%. 2. A systematic investigation of potential ligands has been carried out: these included 6-phosphogluconate and NADP+, pyridoxal phosphate and several immobilized nucleotides. The results indicate that NADP+ is the most suitable ligand for the purification of 6-phosphogluconate dehydrogenase. 3. The effects of pH and alternative eluents have been examined in relation to the parameters known to affect the desorption phase of affinity chromatography; careful manipulation of the elution conditions permitted the separation of glucose 6-phosphate dehydrogenase, glutathione reductase and 6-phosphogluconate dehydrogenase from sheep liver on NADP+-Sepharose 4B. 4. A large-scale purification scheme for 6-phosphogluconate dehydrogenase is presented that uses the competitive inhibitors inorganic pyrophosphate and citrate as specific eluents.

Animals↗