Characterization of two thioredoxins in pig heart including a new mitochondrial protein.
Heart tissue contains two different thioredoxins. One is a specific mitochondrial protein and is best prepared from pre-isolated, intact heart mitochondria (mt-thioredoxin) whereas mitochondria-depleted tissue homogenates contain the major cellular thioredoxin of cytoplasmic origin (c-thioredoxin). Both heat-stable proteins are clearly differentiated chromatographically. They exhibit slightly different molecular weights (12,300 vs. 12,000) and isoelectric points (4.7 vs. 4.8) but differ remarkably in their cysteine content: mt-Thioredoxin has two cysteine residues like the bacterial proteins, and c-thioredoxin possesses six cysteines. Heart extracts were also shown to contain a NADPH-specific thioredoxin reductase of the known mammalian type. A specific function or target enzyme of mt-thioredoxin has not as yet been established.
Bodenstein
J
J
Universität Kassel, Bundesrepublik Deutschland.
Follmann
H
H
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003600:Cytosol / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D008929:Mitochondria, Heart / Q000737:chemistry*; D008970:Molecular Weight; D009206:Myocardium / Q000737:chemistry* / Q000201:enzymology; D013552:Swine; D013880:Thioredoxin-Disulfide Reductase / Q000302:isolation & purification / Q000378:metabolism*; D013879:Thioredoxins / Q000302:isolation & purification*
D000596:Amino Acids; D013879:Thioredoxins; D013880:Thioredoxin-Disulfide Reductase