Method for simultaneously monitoring turnover rate in multiple proteins

DETAILED DESCRIPTION The invention provides an assay method for cellular and extracellular protein biodynamics comprising the use of radiochemical techniques in combination with high resolution protein separation procedures and recently developed silver stain techniques, to assess turnover of polypeptides over time.
It has unexpectedly been found that the use of .
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14 C-labelled precursors permits the use of radiolabelling techniques in conjunction with silver staining methods for polypeptides in gels, and by the simple, yet highly sensitive, process of the invention, net synthesis or degradation in vivo or in vitro of specific proteins under varying experimental conditions may be quantified.
Exemplary conditions are those promoting homeostasis, or those conditions which stimulate or reduce protein synthesis.
The process of the invention is particularly useful in both research and diagnostic applications for quantifying multiple protein turnover rates.
Potential applications include evaluation of trauma or in monitoring genetically altered microbes.
For example, central nervous system damage might be evaluated by a determination of the rate of exchange of albumin between blood and spinal fluid.
In this determination, radio-labelled (.
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125 I) iodine would be injected intravenously, and the specific activity (.
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125 I-albumin/total albumin)in the spinal fluid measured.
Alternatively, in genetic engineering applications, microbial production of critical enzymes can be monitored by the present process, for example by measuring specific activities (by pulse labelling) under different growth conditions.
Production of specific cell enzymes can thus be maximized.
The process of the present application further is useful in a number of research applications, for example, in mutagenesis assays.
Alterations in cellular protein synthesis owing to mutation of controlling genes can be assessed by combining silver staining methods and high resolution protein separation techniques, in conjunction with radioactive labelling, as described herein