Applications of polyacrylamide gel electrophoresis and polyacrylamide gel isoelectric focusing in clinical chemistry

Author(s):  
Robert C. Allen
1979 ◽  
Vol 90 (4) ◽  
pp. 737-742 ◽  
Author(s):  
W. Mischke ◽  
H. C. Weise ◽  
D. Graesslin ◽  
R. Rusch ◽  
J. Tamm

ABSTRACT Highly purified sex hormone binding globulin (SHBG) was isolated in milligram amounts from a human serum fraction (Cohn IV-4). The final preparation was homogeneous by the criteria of polyacrylamide-gel electrophoresis. Immunological evidence for purity could be given by double diffusion according to Ouchterlony. However, following gel isoelectric focusing highly purified SHBG displayed four different bands, as could be demonstrated by staining as well as by a photoscan of the [3H]5α-dihydrotestosterone-SHBG complex. After incubation with neuraminidase the microheterogeneity of SHBG disappeared and the asialo-SHBG showed only one band.


1988 ◽  
Vol 253 (1) ◽  
pp. 263-267 ◽  
Author(s):  
I Vancurová ◽  
J Volc ◽  
M Flieger ◽  
J Neuzil ◽  
J Novotná ◽  
...  

Anhydrotetracycline oxygenase was purified to homogeneity from Streptomyces aureofaciens, a producer of tetracycline. The enzyme was purified 60-fold in a 40% yield by a two-step procedure using a combination of hydrophobic chromatography and ion-exchange h.p.l.c. Purified anhydrotetracycline oxygenase was homogeneous according to SDS/polyacrylamide-gel electrophoresis, isoelectric focusing, ion-exchange h.p.l.c. on a Mono Q HR 5/5 column and size-exclusion h.p.l.c. on a TSK G 3000 SW column. The enzyme consists of two subunits of Mr 57,500, as determined by SDS/polyacrylamide-gel electrophoresis.


1978 ◽  
Vol 173 (3) ◽  
pp. 759-765 ◽  
Author(s):  
J A Sharp ◽  
M R Edwards

CoA-transferase (succinyl-CoA-3-oxo acid CoA-transferase, EC 2.8.3.5) isolated from sheep kidney was purified to homogeneity. The purified enzyme has a specific activity of approx. 200 units/mg. A mol.wt. of 110000 was obtained by gel filtration on Sephadex G-200, and a lower mol.wt. of 102000 was determined by analytical ultracentrifugation. A sedimentation coefficient of 5.6S was also determined. A subunit mol.wt. of 56000 was obtained by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Isoelectric focusing of sheep kidney extracts indicated the presence of a single band of CoA-transferase activity with pI9.0. However, isoelectric focusing of purified CoA-transferase showed the presence of two peaks of CoA-transferase activity with pI values of 8.7 and 8.4, suggesting the presence of proteolytic activity during purification. Evidence for sheep kidney CoA-transferase being a dimer of two identical subunits has been obtained from sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, the amino acid composition, peptide ‘mapping’ and N-terminal analysis.


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