Distribution of Soluble Proteins Within Spinal Motoneurons: A Quantitative Two‐Dimensional Electrophoretic Analysis

Abstract

Soluble protein fractions obtained from bovine lumbar spinal motoneuron cell bodies, ventral gray matter, and ventral and dorsal roots were analyzed by two-dimensional gel electrophoresis. Each extract was separated into Coomassie blue-stained patterns of up to 350 polypeptides ranging in isoelectric point from pH 4 to 8 and in molecular weight from 10,000 to 200,000. Visual inspection of the protein pattern of the isolated cell bodies showed it to be substantially different from those of ventral gray matter and the spinal roots, while the patterns obtained from ventral and dorsal roots were indistinguishable. Computer-assisted densitometry of the major soluble proteins from spinal roots showed no quantitative difference between the predominant proteins in ventral and dorsal root extracts. Differences of 10-fold or more were common when the major proteins of the isolated perikarya were compared with those of the other fractions. Since most of the soluble proteins extracted from ventral and dorsal roots were probably derived from the axoplasm of motor and sensory nerves, respectively, these results are interpreted to mean that large differences exist in the distribution of individual soluble proteins between the cell body and axon of spinal motoneurons, while the major soluble proteins of spinal motor and sensory axons are highly similar.

Proteins Regulated by Gonadal Steroids in the Medial Preoptic and Ventromedial Hypothalamic Nuclei of Male and Female Rats

“…Albumin is by far the most prominent protein in blood and has been reported to be the most readily detectable protein on silver-stained gels, when blood plasma samples in amounts greater than would be present in our whole tissue preparation are run on twodimensional gels [51]. As with 9+11, intact males had higher densities of albumin in the MPO than any other group, and estrus females had the highest densities in in VMH, significantly different than gonadectomized females.…”

“…Protein 12 is albumin from blood serum remaining in the tissue following decapitation [51,53]. Albumin is by far the most prominent protein in blood and has been reported to be the most readily detectable protein on silver-stained gels, when blood plasma samples in amounts greater than would be present in our whole tissue preparation are run on twodimensional gels [51].…”

Mapping and quantitation of proteins from discrete nuclei and other areas of the rat brain by two-dimensional gel electrophoresis

“…Tentaareas. Protein number 52, however, appears to be almost tive assignments, based on previously published reports (Wilson et al, 1977;Hall et al, 1978;Merril et al, 1981b; totally absent from the dorsomedial nucleus of the hy- Weil and McIlwain, 1981;Goldman et al, 1982) can be pothalamus, whereas it is found in significant amounts in the entorhinal cortex. This is confirmed when com-made for actin (spot 22) and P-tubulin (spot 13).…”

“…Subpopulations of neuronal tissue have successfully been mapped by 2DE. Examples of this include the soluble proteins from bovine spinal motoneurons (Weil and McIlwain, 1981) and neurofilament proteins from rat and mouse central nervous system (Brown et al, 1981). Again, although significant changes among various experimental groups are reported, such studies also fail to provide a generalized index of all proteins normally present in neuronal tissue.…”

Identification of Neuron‐Specific Enolase and Nonneuronal Enolase in Human and Rat Brain on Two‐Dimensional Polyacrylamide Gels

“…Unfortunately, one shortcoming of these studies is that the identity of most proteins visualized on two-dimensional gels generated from samples of nervous tissue is unknown. Tentative assignments, based on previously published reports (Wilson et al, 1977;Hall et al,, 1978;Merril et al, 1981~;Weil and McIlwain, 1981;Goldman et al, 1982), can be made for actin, (Y and p tubulin, and serum albumin.…”