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C L Parfett

Publications and source records attributed to C L Parfett.

24 records · Page 2Linked to original sources
PubMed1984

Concanavalin A binding to fibroblasts from Duchenne muscular dystrophy patients and age-matched controls.

An investigation of [125I]Con A binding to skin fibroblasts from Duchenne muscular dystrophy patients and age-matched controls was carried out. The age groups examined were 5-6 years, 11-12 years, and 15-17 years. Only small differences in binding abilities were observed between dystrophic cells and matched controls. When data was examined as micrograms Con A bound/micrograms protein, dystrophic fibroblasts bound slightly more lectin compared to controls with the 5-6 and 11-12 year age groups, whereas the 15-17 years age group bound slightly less Con A compared to normal controls. However, analysis of binding data as lectin bound/cell showed slightly reduced binding of Con A to dystrophic cells from all age groups when compared to matched controls. It was also found that the amount of Con A bound by both normal and dystrophic fibroblasts markedly increased with the age of the donor. Obviously several factors must be taken into account when analyzing lectin binding data obtained with human fibroblasts. Taken as a whole, our studies do not provide evidence for significant modification of cell surface Con A receptors on fibroblasts from Duchenne muscular dystrophy patients.

Adolescent↗
PubMed1983

Changes in cell surface glycoproteins on non-differentiating L6 rat myoblasts selected for resistance to concanavalin A.

Four independently selected conA-resistant, non-differentiating rat L6 myoblast cell lines and their parental wild-type populations were examined for cell surface alterations. [3H]conA-binding studies indicated that the variant myoblasts bound significantly less lectin than wild-type cells at 4 and at 37 degrees C. Scatchard analysis revealed two general types of binding sites (high and low affinity sites) on wild-type cells; the variants appeared to be deficient in the high affinity sites. These changes in conA binding probably play an important role in determining the conA-resistant phenotype. Lectin-binding results could be significantly modified by altering the composition of the serum in the growth medium used to culture myoblasts prior to performing binding experiments, suggesting the existence of productive and non-productive lectin-binding sites on the cell surface. SDS slab gel electrophoresis of [3H]mannose-labelled surface membranes prepared from variant and wild-type cells showed that several glycoproteins of the conA-resistant myoblasts were defective in mannosylation. The conA-binding abilities of a pronase digest of one of these altered regions from variant separations, with a molecular weight of 44500 D, was found to contain glycopeptides with reduced affinity for the lectin, supporting the idea that variant membranes are deficient in a set of high affinity lectin-binding sites. Studies on [GDP-14C]mannose incorporation into lipid by membranes from variant and wild-type myoblasts indicated that the biosynthetic lesion likely involved a mannosyl transferase enzyme directly, rather than a lack of free dolichol-PO4. These studies link conA resistance, cell surface glycoprotein alterations, and defective mannosyl transferase activity with the inability to carry out normal cellular differentiation to form multinucleated myotubes.

Animals↗
PubMed1980

Somatic cell genetics: a review of drug resistance, lectin resistance and gene transfer in mammalian cells in culture.

During the past decade development of selection procedures for isolating a large variety of altered stable phenotypes in mammalian cell culture has been extremely rapid. The list now includes temperature sensitive, auxotrophic, drug resistant and lectin resistant cell lines, as well as cultures containing altered products of differentiation. As a general class, the drug resistant mutants have been studied more often than any of the others because of the wide variety of very interesting and specifically altered mutants that can be isolated, and the ease with which they can usually be obtained. In this review we discuss the essential features of the best studied drug and lectin resistant systems. Also a section on gene transfer has been included since the new technology being developed in this area is certain to have great influence on our understanding of fundamental aspects of somatic cell variation.

Amanitins↗