scholarly journals Peptide analysis of collagen produced from cDNA by transcription and translation in vitro

1987 ◽  
Vol 245 (2) ◽  
pp. 393-398 ◽  
Author(s):  
J F Bateman ◽  
S Lamande ◽  
D Chan ◽  
W G Cole

When collagen CNBr-cleavage peptides are analysed by two-dimensional gel electrophoresis each peptide is resolved into a reproducible set of charged forms. To test whether this peptide heterogeneity resulted from polymorphic mRNA, collagen was produced by transcription and translation in vitro of a collagen cDNA clone, and the peptides were mapped by two-dimensional gel electrophoresis. A cDNA construct was produced by ligation of the 5′ end of the rat phenylalanine hydroxylase cDNA [Dahl & Mercer (1986) J. Biol. Chem. 261, 4148-4153], containing the translation-initiation codon, to a human alpha 1(I) cDNA [Chu, Myers, Bernard, Ding & Ramirez (1982) Nucleic Acids Res. 10, 5925-5934] coding for a large portion of helical region including the complete CB7 and CB3 CNBr-cleavage peptides. This cDNA construct was ligated into the transcription vector pSP65, and cell-free translation of the mRNA transcribed from the pSP65 plasmid was performed with a rabbit reticulocyte lysate system. After CNBr cleavage of the hybrid protein translation products, the collagen CB7 and CB3 peptides were resolved by two-dimensional electrophoresis into the same multiple charged forms whether the mRNA was produced from the cDNA construct or was extracted from normal fibroblast cultures. This result demonstrated that the multiple peptide spots were not due to polymorphic mRNA species. The heterogeneity must result from some uncharacterized specific post-translational modification or chemical alterations during sample preparation. This method of expression and analysis of proteins from cDNA clones should be of considerable use in the identification and characterization of clones that code for mutant proteins.

1981 ◽  
Vol 91 (2) ◽  
pp. 352-360 ◽  
Author(s):  
TW McKeithan ◽  
JL Rosenbaum

The alga polytomella contains several organelles composed of microtubules, including four flagella and hundreds of cytoskeletal microtubules. Brown and co-workers have shown (1976. J. Cell Biol. 69:6-125; 1978, Exp. Cell Res. 117: 313-324) that the flagella could be removed and the cytoskeletans dissociated, and that both structures could partially regenerate in the absence of protein synthesis. Because of this, and because both the flagella and the cytoskeletons can be isolated intact, this organism is particularly suitable for studying tubulin heterogeneity and the incorporation of specific tubulins into different microtubule-containing organelles in the same cell. In order to define the different species of tubulin in polytonella cytoplasm, a (35)S- labeled cytoplasmic fraction was subjected to two cycles of assembly and disassembly in the presence of unlabeled brain tubulin. Comparison of the labeled polytomella cytoplasmic tubulin obtained by this procedure with the tubulin of isolated polytomella flagella by two-dimensional gel electrophoresis showed that, whereas the β-tubulin from both cytoplasmic and flagellar tubulin samples comigrated, the two α-tubulins had distinctly different isoelectic points. As a second method of isolating tubulin from the cytoplasm, cells were gently lysed with detergent and intact cytoskeletons obtained. When these cytoskeletons were exposed to cold temperature, the proteins that were released were found to be highly enriched in tubulin; this tubulin, by itself, could be assembled into microtubules in vitro. The predominant α-tubulin of this in vitro- assembled cytoskeletal tubulin corresponded to the major cytoplasmic α-tubulin obtained by coassembly of labeled polytomella cytoplasmic extract with brain tubulin and was quite distinct from the α-tubulin of purified flagella. These results clearly show that two different microtubule-containing organelles from the same cell are composed of distinct tubulins.


1973 ◽  
Vol 29 (01) ◽  
pp. 122-129 ◽  
Author(s):  
René von Hugo ◽  
Henner Graeff

SummaryThe observation of intravascular lysis of fibrin deposits and of fibrinogen derivatives with a molecular weight higher than the parent molecule in human cases of disseminated intravascular coagulation (DIC) initiated the following in vitro study. Following streptokinase induced plasma clot solubilization fibrinogen derivatives were investigated after ß-alanine precipitation of the plasma samples by polyacrylamide (PAA) gel electrophoresis, intra gel immunoprecipitation, two dimensional gel electrophoresis and by agarose gel filtration. Three fibrin-i degradation products were observed and characterized according to their relative electrophoretic mobility in 5% PAA gel: 0.23, 0.35, 0.46 (fibrinogen: 0.43) x 10-5 cm2/V x sec. They could also be demonstrated after electrophoresis in the presence of 5 M urea. Agarose gel filtration yielded one peak at 180 ml of effluent volume. The 0.23 derivative was eluted in the peak fractions, whilst the 0.35 and 0.46 derivatives were eluted together at approximately 201 ml of the effluent volume (fibrinogen: 225 ml). This indicates, that the three fibrin-i degradation products described are molecular entities with molecular weights higher than fibrinogen and, that the 0.46 derivative has an increased charge/molecular size ratio in comparison with fibrinogen. Corresponding data were obtained by two dimensional gel electrophoresis in gels of different pore size.


1984 ◽  
Vol 217 (1) ◽  
pp. 145-157 ◽  
Author(s):  
M A Kaderbhai ◽  
B M Austen

The two-dimensional polyacrylamide-gel electrophoresis technique of O'Farrell [(1975) J. Biol. Chem 250, 4007-4021] was applied to resolve and analyse the polypeptide composition of dog pancreatic rough microsomal membranes, which were shown to be active in co-translational processing of preprolactin synthesized from pituitary mRNA in a translation system in vitro. About 100 polypeptides are resolved. Treatment of rough microsomal membranes with EDTA and high KCl concentration yielded membranes stripped of their ribosomes with retention of activity for translocation and processing. Stripped microsomal membranes showed a selective concentration of approximately 25 polypeptides in the membranes when analysed by two-dimensional polyacrylamide-gel electrophoresis. The two-dimensional electrophoretic profile was catalogued into polypeptides that are glycoproteins, those that contain free thiol groups disposed at the cytosolic surface of microsomal vesicles and those that are of secretory origin but have been entrapped in the microsomal preparation. Several secretory components, including amylase, procarboxypeptidases, lipase and anionic trypsinogen, were tentatively identified among the microsomal polypeptides. The rough and stripped microsomal membranes from dog pancreas show a characteristic set of seven major acidic polypeptides, which are also identifiable in microsomal-membrane preparations isolated from dog liver and rat liver. One of these polypeptides was identified as protein disulphide-isomerase (EC 5.3.4.1).


Development ◽  
1985 ◽  
Vol 89 (1) ◽  
pp. 275-287
Author(s):  
William R. Jeffery

The yellow crescent or myoplasm is a localized cytoplasmic region in eggs of the ascidian Styela that is partitioned to the larval tail muscle and mesenchyme cells during embryonic development. To determine whether the myoplasm contains a specific subset of maternal macromolecules, its abundant proteins and mRNAs were identified and compared to those present in the remainder of the egg. This was accomplished by exploiting a newly developed method for the mass fractionation of yellow crescents which is based on the presence of a unique cytoskeletal domain in the yellow crescent region. The fractionation yields a yellow crescent fraction (YCF) representing the myoplasm and a supernatant fraction representing the nonmyoplasmic regions. The YCF comprises structures which contain the characteristic myoplasmic organelles and about 10% of the protein, 8% of the RNA, and 1–3% of the poly (A) of whole eggs. Two-dimensional gel electrophoresis indicated that the YCF contains 15 polypeptides that are undetectable in the supernatant fraction and 43 polypeptides that are significantly depleted in the latter fraction. The proteins restricted to the YCF are both of cytoskeletal and noncytoskeletal origin. In vitro translation of RNA in a message-dependent lysate and analysis of [35S]methionine-labelled polypeptide products by two-dimensional gel electrophoresis did not reveal qualitative differences between the YCF and the supernatant fraction. Furthermore, the mRNAs coding for two polypeptides that were localized in the myoplasm were not restricted to the YCF. The results suggest that qualitative differences in proteins but not in prevalent mRNAs exist between the yellow crescent and the other cytoplasmic regions of Styela eggs.


1984 ◽  
Vol 30 (12) ◽  
pp. 1996-2002 ◽  
Author(s):  
D M Jacobowitz ◽  
W E Heydorn

Abstract Using two-dimensional gel electrophoresis, we studied proteins in the rat brain. The relative amounts of individual proteins differ in discrete areas of the brain, and the concentrations of three different proteins can be altered by chronic administration of desmethylimipramine or reserpine. Brain proteins can be radiolabeled in vitro by incubating samples of fresh tissue with [35S]methionine. We identified several proteins by using immunoblotting and comigration. Finally, we developed a possible animal model for studying proteins related to Alzheimer's disease by depleting the cholinergic innervation to the cortex and the hippocampus.


1985 ◽  
Vol 63 (7) ◽  
pp. 705-710 ◽  
Author(s):  
Pierre Chapdelaine ◽  
Jean Y. Dubé ◽  
Gilles Frenette ◽  
Roland R. Tremblay

Poly(A)+ rich RNA was isolated from prostate of adult dogs and translated in the rabbit reticulocyte lysate cell-free protein-synthesizing system. Two-dimensional gel electrophoresis of the translation products showed that a protein with a molecular weight of 31 000 was predominantly synthesized. This protein was immunoprecipitated with antibodies directed against purified arginine esterase from dog seminal plasma. mRNA isolated from the prostate of animals castrated for 1 or 2 weeks was unable to direct the synthesis of arginine esterase. However, the synthesis of the enzyme could be stimulated by androgens in castrated animals, presumably by increasing prostatic concentrations of arginine esterase mRNA. The single chain translation product could be further processed in vitro by the addition of dog pancreas microsomes and purified arginine esterase. This procedure yielded split chains of arginine esterase which had identical electrophoretic mobilities as seminal plasma enzyme by two-dimensional gel electrophoresis. When prostatic tissue slices were incubated with tunicamycin, the unglycosylated arginine esterase obtained had a lower molecular weight than the in vitro translation product, suggesting that a signal peptide had been removed in the living cells. These results indicate that arginine esterase processing may include the following steps: removal of a signal peptide, glycosylation, and splitting of the polypeptide chain by active arginine esterase in the secretory granules or outside the cell.


1982 ◽  
Vol 58 (1) ◽  
pp. 35-48
Author(s):  
R.L. Shoeman ◽  
H.G. Schweiger

The translation products induced by poly(A)+ RNA from Acetabularia mediterranea, A. cliftonii and A. ryukyuensis in a modified, highly efficient wheat germ cell-free in vitro system were separated by two-dimensional gel electrophoresis. A comparison of the translation products on the basis of their molecular weight and their isoelectric point revealed only a limited similarity between the patterns of the three species. The pronounced species specificity will permit the study of the in vivo translation of heterologous poly(A)+ RNA in Acetabularia cytoplasm.


1983 ◽  
Vol 3 (8) ◽  
pp. 1412-1420
Author(s):  
Y D Plancke ◽  
E Lazarides

Phosphocalmodulin (PCaM) was identified after analysis of calmodulin (CaM) preparations by two-dimensional gel electrophoresis by using a modified ampholyte system to resolve very acidic proteins. The analysis of CaM prepared by the conventional procedure based upon its heat resistance and acidity as well as the analysis of whole urea extracts from brain showed that PCaM was a major component in this tissue. PCaM was 1 pH unit more acidic than CaM, and its electrophoretic mobility, unlike CaM, was not changed by either calcium or ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid. In urea extracts of brain prepared in buffers containing phosphate and sodium fluoride, PCaM was as prominent as CaM; it was partially converted into CaM after elution from the gel and reelectrophoresis. Amino acid analysis of PCaM and CaM purified by two-dimensional gel electrophoresis showed the same composition for the two proteins, including their trimethyllysine content. Incorporation of 32P occurred exclusively into the acidic variant when brain slices were incubated with H332PO4; amino acid analysis showed that the phosphate was bound to serine residues. CaM was found also to be phosphorylated in vitro by a phosphorylase kinase preparation from skeletal muscle.


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