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N Buttress

Publications and source records attributed to N Buttress.

13 recordsLinked to original sources
PubMed1993

The International Standard for Thyroxine Binding Globulin.

OBJECTIVE: Thyroxine binding globulin is the major thyroid hormone binding and transport protein of the plasma, and its quantitative estimation is therefore of clinical importance. The objectives of the present study were to prepare and ampoule a preparation of thyroxine binding globulin suitable to serve as an international standard, to confirm the suitability of the preparation in a multi-centre collaborative study, and to assign an ampoule content. DESIGN: The collaborative study was designed with the following aims: (1) to compare the candidate preparation with local standards; (2) to calibrate the preparation with local standards and to confirm the assigned ampoule content; (3) to assess the stability of the ampouled preparation. MEASUREMENTS AND RESULTS: Thyroxine binding globulin was purified by a combination of affinity and conventional chromatography. Analysis by gel electrophoresis, N-terminal sequencing and electrospray mass spectroscopy showed the preparation to be > 99% pure and to have a structure consistent with the known structure of thyroxine binding globulin. Thyroxine binding globulin assays performed in the multi-centre collaborative study indicated that the preparation behaved as thyroxine binding globulin when compared to local standards and that the ampoule content was consistent with that assigned on the basis of physicochemical measurements of protein concentration. CONCLUSIONS: The thyroxine binding globulin preparation coded 88/638 was established by the Expert Committee on Biological Standardization of the World Health Organization as the International Standard for Thyroxine Binding Globulin, 30.0 International Units per ampoule, with the additional information that for the preparation in 88/638, 1 IU is equivalent to 1 microgram. The preparation is available from the National Institute for Biological Standards and Control.

Chromatography, Affinity↗
PubMed1987

Isolation and characterisation of goat C-reactive protein.

A pentraxin was isolated from acute phase goat serum by its calcium-dependent affinity for agarose, and although it did not bind to phosphorylcholine immobilised on Sepharose, its binding to agarose was reversed by exposure to fluid phase phosphorylcholine. It was identified as goat C-reactive protein on the basis of its immunochemical cross-reactivity with human and bovine C-reactive protein. The molecule was composed of five identical, glycosylated, non-covalently associated subunits, each of molecular weight approx. 24,000. Acute phase serum levels in a small number of samples were not significantly different from normal levels (means 72 and 55 micrograms/ml, respectively), suggesting that goat C-reactive protein is not a major acute phase reactant. No other pentraxin was detected in goat serum.

Animals↗
PubMed1986

Isolation and characterization of guinea-pig serum amyloid P component.

A pentraxin was isolated from acute-phase guinea-pig serum by calcium-dependent affinity chromatography on agarose. It was immunochemically identical to guinea-pig amyloid P component and therefore has been called guinea-pig serum amyloid P component (SAP). Guinea-pig SAP has an apparent MW of between 265,000 and 300,000 by different techniques, and is composed of 10 noncovalently associated subunits arranged in two pentameric annular discs interacting face-to-face. It is apparently composed of two types of subunit, which run as a closely spaced doublet on reduced sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). At least one type of subunit is glycosylated. The serum concentration was 16 +/- 4 mg/l in outbred animals, rising to 25 +/- 4 mg/l in an acute-phase response. Binding to agarose correlated with the agarose pyruvate content and was completely abolished by diazomethane treatment of the agarose, which methylates the pyruvate carboxylic moiety. Binding was also inhibited in the presence of free methyl 4,6-o-(carboxyethylidine)-beta-D-galactopyranoside. No protein resembling C-reactive protein (CRP) was obtained by calcium-dependent affinity chromatography of acute-phase guinea-pig serum on phosphorylcholine (PC)-Sepharose, and it not clear whether a counterpart of CRP exists in this species.

Animals↗
PubMed1984

Isolation and characterization of C-reactive protein from the dog.

Using calcium-dependent affinity chromatography on Sepharose-bearing, covalently-coupled pneumococcal C-polysaccharide, a protein was isolated from the serum of dogs that had undergone general anaesthesia and major surgery. This protein was confirmed as the canine analogue of C-reactive protein (CRP) in other species by virtue of its electron microscopic appearance, subunit composition and behaviour as an acute phase reactant. Dog CRP had an apparent molecular weight of approximately 100,000 and was composed of five subunits of approximately 20,000 MW each. Two of the five subunits in each molecule were glycosylated. Negatively stained preparations had the typical cyclic pentameric disc-like structure of proteins of the pentraxin family, and in some preparations had a tendency to form stacks. Serum from normal healthy dogs of various strains usually contained less than 5 mg/l of CRP but, following the stimulus of major surgery, an increase in the CRP concentration was first detected at 4 hr.

Animals↗
PubMed1979

Plasma lipids and lipoproteins of some members of the order Perissodactyla.

1. The plasma lipoproteins of various members of the order Perissodactyla have been examined by electrophoresis and analytical ultracentrifugation. 2. In the Equidae, high density (alpha) lipoprotein was the major component (80-90%) and low density (beta) lipoprotein (10-20%) the minor component. 3. In the Tapiridae represented by the Malayan tapir (Tapirus indicus), high density and low density lipoproteins were present in approximately equal amounts. 4. In the Rhinocerotidae, the high density lipoprotein characteristic of the Equidae and Tapiridae was absent, and the plasma lipoproteins consisted of a complex group having beta mobility on electrophoresis and a flotation pattern usually associated with low density lipoprotein. 5. The fatty acid composition of plasma lipids was remarkably similar in all members of the Perissodactyla examined, with very high percentages of linoleic acid (greater than 70%) being found in the cholesteryl esters.

Animals↗
PubMed1976

Plasma lipoproteins of lambs and sheep.

The major plasma lipoproteins of the adult sheep were high density lipoprotein (76%) having alpha-mobility on electrophoresis and low density lipoprotein (20%) having beta-mobility. Chylomicrons and very low density lipoproteins were minor constituents (less than 5%). The postabsorptive hyperlipidaemia in suckling lambs is mainly a result of increased concentration of low density and high density lipoproteins although the relative contribution of very low density lipoproteins was increased to 7-15% of the total lipoproteins. The hyperlipiaemia was markedly greater in an intact male lamb than in female or castrated male lambs. In suckling lambs a new lipoprotein (density 1-090 g/ml) appeared in the high density lipoprotein fraction but disappeared before weaning.

Age Factors↗
PubMed1973

Structural studies on individual components of bovine transferrin.

The single-banding components of bovine transferrin from animals homozygous for the four transferrin variants found in the U.K. were isolated. Sedimentation equilibrium ultracentrifugation and sodium dodecyl sulphate-polyacrylamide-gel electrophoresis showed that the bands of a single variant have molecular weights of 77500 and 73300 respectively. The different bands of a single variant and single bands of different variants show no evidence of size heterogeneity or of low-molecular-weight peptides being split off after reduction in 6m-guanidine hydrochloride. The two slower bands of a single variant, which both contain 2 molecules of sialic acid/molecule of protein, have the same molecular weight and amino acid composition, and give identical peptide ;maps', although differences in composition and peptide ;maps' occur between the different variants. The results support the concept that bovine transferrin is essentially a single polypeptide chain, but they do not explain differences in electrophoretic mobility between bands of the same variant which are not produced by differing sialic acid content.

Amino Acids↗