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Biomedical subjects

N L Anderson

Publications and source records attributed to N L Anderson.

At least 19 recordsLinked to original sources
PubMed1992

Two-dimensional gel electrophoresis analysis of Syrian hamster embryo cells: morphological transformation is not cell type specific.

Studies were conducted to investigate the protein phenotype of normal and morphologically transformed Syrian hamster embryo (SHE) cells. Based upon two-dimensional gel protein phenotype analysis, we conclude that (i) SHE cells are a mixture of multiple cell types including mesenchymal and epithelial cells and (ii) several cell types present in the SHE cell population can be morphologically transformed by a variety of genotoxic and non-genotoxic carcinogens.

Animals↗
PubMed1992

Covalent protein modifications and gene expression changes in rodent liver following administration of methapyrilene: a study using two-dimensional electrophoresis.

The effect of methapyrilene (MP), a mitochondrial proliferator and presumed nongenotoxic carcinogen, has been examined in rodent liver by means of high-resolution two-dimensional electrophoretic analysis of total proteins. Using this approach, we have discovered protein modifications in rat liver resulting from 1 week MP treatment that suggest the involvement of a reactive drug metabolite. The restriction of these molecular charge modifications to mitochondrial proteins indicates that such a reactive metabolite must be generated and confined within the mitochondrion. Quantitative changes in numerous nonmitochondrial proteins are also observed. Following a 4-week recovery period, almost all the 1-week treatment changes are reversed, reestablishing a protein pattern close to that of the controls. At the end of a 10-week exposure, the mitochondrial protein modifications are increased and are accompanied by a variety of quantitative protein changes indicative of a large shift in gene expression and/or cell type composition. When a 4-week untreated recovery period follows the 10-week treatment, small quantitative changes persist. In the mouse, where MP appears not to induce mitochondrial proliferation or tumorigenesis, 1 week treatment nevertheless produces mitochondrial protein changes in vivo consistent with attack by a reactive metabolite, but at a level substantially lower than that seen in the rat. Features of the mitochondrial protein modification indicate that it is covalent, does not involve cysteine or tryptophan, and results from binding of a negatively charged adduct. The possibility that the putative reactive metabolite could also attack mitochondrial (but not nuclear) DNA suggests that MP could be genotoxic in an unconventional way. Detection of protein modification by two-dimensional gel analysis appears to offer a general method for the detection and characterization of processes generating reactive metabolites.

Animals↗
PubMed1991

A two-dimensional gel database of human plasma proteins.

An updated two-dimensional electrophoretic map of human plasma proteins is presented, together with a complete listing of the individual protein spots, their locations, size and isoelectric points relative to internal charge standards. Forty-nine polypeptide species are identified, many consisting of multiple spots differing in glycosylation or sequence (e.g., immunoglobulins). A further series of 35 as yet uncharacterized proteins is indicated.

Blood Proteins↗
PubMed1991

A two-dimensional gel database of rat liver proteins useful in gene regulation and drug effects studies.

A standard two-dimensional (2-D) protein map of Fischer 344 rat liver (F344MST3) is presented, with a tabular listing of more than 1200 protein species. Sodium dodecyl sulfate (SDS) molecular mass and isoelectric point have been established, based on positions of numerous internal standards. This map has been used to connect and compare hundreds of 2-D gels of rat liver samples from a variety of studies, and forms the nucleus of an expanding database describing rat liver proteins and their regulation by various drugs and toxic agents. An example of such a study, involving regulation of cholesterol synthesis by cholesterol-lowering drugs and a high-cholesterol diet, is presented. Since the map has been obtained with a widely used and highly reproducible 2-D gel system (the Iso-Dalt system), it can be directly related to an expanding body of work in other laboratories.

Animals↗
PubMed1979

Red cell proteins. I. Two-dimensional mapping of human erythrocyte lysate proteins.

Human erythrocyte lysate proteins were resolved into over 250 discrete spots by two-dimensional electrophoresis using isoelectric focusing in the first dimension and electrophoresis in the presence of sodium dodecyl sulfate, (SDS) in the second. The overwhelming excess of hemoglobin has made such analyses difficult in the past. However, with the ISO-DALT two-dimensional electrophoresis system, large numbers of red cell proteins can be mapped in the presence of hemoglobin. When hemoglobin and several other major proteins are removed by adsorption to DEAE-cellulose, additional minor components are seen, giving a total of over 275. With the use of purified preparations, the map positions of five cell enzymes or their subunits were determined: pyruvate kinase, catalase, glucose-6-phosphate dehydrogenase, hypoxanthine phosphoribosyltransferase, and carbonic anhydrase. The mapping techniques described complement and extend those traditionally used to find human red cell protein variants.

Actins↗
PubMed1979

Muscle protein analysis. I. High-resolution two-dimensional electrophoresis of skeletal muscle proteins for analysis of small biopsy samples.

We have been developing a clinically useful method for high-resolution two-dimensional electrophoretic analysis of small (5--10 mg) human muscle biopsy samples with sufficient resolution to resolve the major contractile proteins and enzymes. Using rabbit psoas muscle as a model, we describe methods for sample preparation and two-dimensional electrophoresis. Basic proteins, which appear as streaks when conventional isoelectric focusing is used in the first dimension, are resolved through a modification of the nonequilibrium pH gradient electrophoresis method [Cell 12, 1133 (1977)]. In the two-dimensional patterns obtained from rabbit muscle, we identify the components of 10 enzymes and of myosin, actin, tropomyosin, and troponin. These patterns indicate charge heterogeneity in a large fraction of the proteins. Comparison of rabbit and normal human muscle patterns shows many similarities, but much additional work is required to confirm identifications. We conclude that analysis of small biopsy samples is feasible, but that all aspects of human sample acquisition, storage (when necessary), and preparation require thorough study before the method becomes routine in human muscle research and, ultimately, in the diagnosis of some muscle diseases.

Animals↗
PubMed1976

Hemoglobin St. Louis [beta 28 (B10) Leu replaced by Gln]: crystal structure of the fully reduced (deoxy) form.

The three-dimensional structure of fully reduced Hb St. Louis has been determined to 3.5 A resolution. The difference electron density map clearly shows the site of the mutation and the effects it produces. Glutamine B10 and histidine E7 (the distal histidine) swing towards each other and, between them, stabilize a water molecule in the normally hydrophobic heme pocket. This creation of an aqueous microenvironment near the heme accounts for the thermal instability, high rate of methemoglobin formation, and increased oxygen affinity observed in solution studies of the mutant as described in the preceeding paper. Other than a small increase in tilt of the heme, virtually no further stereochemical disturbances result.

Crystallography↗