Secretion of both partially unfolded and folded apoproteins of dimethyl sulfoxide reductase by spheroplasts from a molybdenum cofactor-deficient mutant of Rhodobacter sphaeroides f. sp. denitrificans.
Spheroplasts prepared from a molybdenum cofactor-deficient mutant of Rhodobacter sphaeroides f. sp. denitrificans secreted dimethyl sulfoxide (DMSO) reductase which had no molybdenum cofactor and therefore no activity, whereas those from wild-type cells secreted the active reductase. The inactive DMSO reductase proteins were separated by nondenaturing electrophoresis into two forms: form I, with the same mobility as the native enzyme, and form II, with slower mobility. Both forms had the same mobility on denaturing gel. Form I and active DMSO reductase had the same profile on gel filtration chromatography. Form II was eluted a little faster than the native enzyme, suggesting that DMSO reductase form II was not an aggregated form but a compactly folded form very similar to the native enzyme. Form II was digested by trypsin and denatured with urea, whereas form I was unaffected, like native DMSO reductase. These results suggested that form II was a partially unfolded but compactly folded apoprotein of DMSO reductase.
Masui
H
H
Department of Biological Science, Faculty of Science, Hiroshima University, Japan.
Satoh
M
M
Satoh
T
T
D001051:Apoenzymes / Q000378:metabolism*; D002850:Chromatography, Gel; D003067:Coenzymes; D004591:Electrophoresis, Polyacrylamide Gel; D007506:Iron-Sulfur Proteins; D008667:Metalloproteins / Q000378:metabolism*; D000090006:Molybdenum Cofactors; D009154:Mutation; D010088:Oxidoreductases / Q000378:metabolism*; D011487:Protein Conformation; D011621:Pteridines / Q000378:metabolism*; D012242:Rhodobacter sphaeroides / Q000201:enzymology*; D013104:Spheroplasts / Q000201:enzymology*; D014357:Trypsin / Q000378:metabolism; D014508:Urea / Q000378:metabolism
D001051:Apoenzymes; D003067:Coenzymes; D007506:Iron-Sulfur Proteins; D008667:Metalloproteins; D000090006:Molybdenum Cofactors; D010088:Oxidoreductases; D011621:Pteridines; D014357:Trypsin; D014508:Urea; C022261:molybdopterin; C045664:dimethyl sulfoxide reductase