Stephen L. Burbeck

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Two different mutant human beta-actin genes have been introduced into normal diploid human (KD) fibroblasts and their immortalized derivative cell line, HuT-12, to assess the impact of an abnormal cytoskeletal protein on cellular phenotypes such as morphology, growth characteristics, and properties relating to the neoplastic phenotype. A mutant beta-actin(More)
We identified six tropomyosin (Tm) isoforms in diploid human fibroblasts. We used computerized microdensitometry of 2-dimensional protein profiles to measure the relative rates of synthesis and abundance of the individual Tm isoforms and actin, the two major structural constituents of microfilaments. In carcinogen-transformed human fibroblasts (HuT-14), the(More)
Mutant human beta-actin genes were introduced into normal human (KD) fibroblasts and the derivative cell line HuT-12, which is immortalized but nontumorigenic, to test their ability to promote conversion to the tumorigenic state. Transfected substrains of HuT-12 fibroblasts that expressed abundant levels of mutant beta-actin (Gly-244----Asp-244) produced(More)
We present a method that can, in principle, provide tentative identification of a substantial proportion of the polypeptides resolvable on a given two-dimensional electrophoresis gel. Computerized microdensitometry of autoradiograms from 20 gels labeled in turn with each of the 20 common amino acids provides the data for simultaneously measuring the amino(More)
The transformation-induced protein plastin (p219; Mr 68,000, pl 5.3) is a reliable cytosolic marker for neoplastic human fibroblasts. Fibroblasts transformed in vitro by chemical carcinogens or SV40 virus and tumor-derived cancer cells of fibroblastoid or epithelioid origin usually express plastin and p220, a minor phosphorylated form of plastin. We report(More)
The mass profiles of urine samples and their reproducibility (coefficient of variation) obtained by field-ionization mass spectrometry (volcano source) depend upon the choice of normalization method. We compared six different normalization techniques in terms of improved reproducibility and sensitivity. Several simple procedures markedly improved(More)
We report the amino acid composition of two polypeptides, p788 and p789. These polypeptides are reliable markers for neoplastic transformation in human fibroblasts. Their compositions are unusually rich in cysteine and serine. Because the recently reported amino acid sequence of mouse epidermal growth factor precursor (prepro-EGF) is also rich in those two(More)