Activity, tissue distribution and site-directed mutagenesis of a human peptide methionine sulfoxide reductase of type B: hCBS1.
Human CBS1 is a methionine sulfoxide reductase of type B (MSRB) as it specifically reduced Met-R-SO in peptides with dithiothreitol or the thioredoxin system as reductants. Mutation C169S in the active site completely abolished enzymatic activity, while mutation W110A only reduced activity and C105S had no effect. Like human MSRA, hCBS1 showed in vivo reducing activity coexpressed with the Drosophila ShC/B potassium channel in oocytes, by accelerating the overall inactivation time course. hCBS1-encoding mRNA is most abundant in muscle tissues, especially in the heart and thereby shows an expression pattern different to the human MSRA.
Jung
Stephan
S
Molecular and Cellular Biophysics, Medical Faculty of the Friedrich Schiller University Jena, Drackendorfer St. 1, D-07747, Jena, Germany.
Hansel
Alfred
A
Kasperczyk
Hubert
H
Hoshi
Toshinori
T
Heinemann
Stefan H
SH
D000818:Animals; D020134:Catalytic Domain; D002478:Cells, Cultured; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D006801:Humans; D013058:Mass Spectrometry; D051150:Methionine Sulfoxide Reductases; D018482:Muscle, Skeletal / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D009206:Myocardium / Q000378:metabolism; D009865:Oocytes / Q000502:physiology; D010088:Oxidoreductases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D015221:Potassium Channels / Q000235:genetics / Q000378:metabolism; D051637:Shaker Superfamily of Potassium Channels; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013237:Stereoisomerism; D014018:Tissue Distribution
D029721:Drosophila Proteins; D010455:Peptides; D015221:Potassium Channels; C496929:Sh protein, Drosophila; D051637:Shaker Superfamily of Potassium Channels; D010088:Oxidoreductases; D051150:Methionine Sulfoxide Reductases; C027219:methionine sulfoxide reductase