Identification of ubiquitin as an immunophilin.
We have identified an 8.4 kDa minor immunophilin from calf thymus and Jurkat T cells as ubiquitin. It binds tacrolimus and sirolimus with K(d)'s of 0.8 and 0.08 nM, respectively. The binding of this protein to cyclosporin A is negligible. Binding of tacrolimus to two commercial sources of ubiquitin, a bovine product, and a recombinant human ubiquitin, was also demonstrated after HPLC purification of the purchased preparations.
Davis
D L
DL
Health Sciences Department, Salisbury State University, Salisbury, Maryland, USA.
Soldin
S J
SJ
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D016572:Cyclosporine / Q000378:metabolism / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D020104:Immunophilins / Q000737:chemistry* / Q000302:isolation & purification; D007166:Immunosuppressive Agents / Q000378:metabolism / Q000494:pharmacology; D019169:Jurkat Cells; D007700:Kinetics; D008969:Molecular Sequence Data; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism; D020123:Sirolimus / Q000378:metabolism / Q000494:pharmacology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D016559:Tacrolimus / Q000378:metabolism / Q000494:pharmacology; D013950:Thymus Gland / Q000737:chemistry; D014452:Ubiquitins / Q000737:chemistry* / Q000302:isolation & purification / Q000502:physiology*
D007166:Immunosuppressive Agents; D011994:Recombinant Proteins; D014452:Ubiquitins; D016572:Cyclosporine; D020104:Immunophilins; D020123:Sirolimus; D016559:Tacrolimus