Molecular diversity of rat brain proteins as revealed by proteomic analysis.

Multiple protein expression forms (MPEFs) presenting splicing forms or co- and posttranslation modifications, account for the vast diversity, the myriad of gene products and clearly indicate problems which proteomics research is facing. In the present study, we generated a rat brain map representing MPEFs by the use of an analytical method based on two-dimensional electrophoresis combined with mass spectrometry. Forty-nine individual proteins were selected that showed more than two spots, resulting altogether into a total number of 357 expression forms.

Depletion of the high-abundance plasma proteins.

Body fluids, like plasma and urine, are comparatively easy to obtain and are useful for the detection of novel diagnostic markers by applying new technologies, like proteomics. However, in plasma, several high-abundance proteins are dominant and repress the signals of the lower-abundance proteins, which then become undetectable either by two-dimensional gels or chromatography. Therefore, depletion of the abundant proteins is a prerequisite for the detection of the low-abundance components.

Proteomic determination of metabolic enzymes of the amnion cell: basis for a possible diagnostic tool?

Amniocentesis is a valuable and standard procedure for prenatal diagnosis of genetic or inborn errors of metabolism. Amnion cells are cultivated and chromosomes or proteins can be examined to provide molecular diagnosis. Mainly individual proteins are searched for based upon pedigrees and/or anamnesis.

Evidence for existence of thirty hypothetical proteins in rat brain.

BACKGROUND: The rapid completion of genome sequences has created an infrastructure of biological information and provided essential information to link genes to gene products, proteins, the building blocks for cellular functions. In addition, genome/cDNA sequences make it possible to predict proteins for which there is no experimental evidence. Clues for function of hypothetical proteins are provided by sequence similarity with proteins of known function in model organisms.

Fractionation of liver proteins by preparative electrophoresis.

Proteomics offers unique possibilities to investigate changes in the levels and modifications of proteins involved in the pathomechanisms of diseases and toxic events. However, search for potential drug targets and disease or toxicity markers is limited by the fact that mainly the high-abundance, hydrophilic proteins are visualized in two-dimensional gels. Here we studied the enrichment of rat liver cytosolic proteins by preparative electrophoresis.