Mammalian FKBP-25 and its associated proteins.
Soluble proteins from porcine brain were divided into two packs: (1) proteins which pass freely through CM52-cellulose, and (2) proteins retained on CM52. Each of these two packs of proteins was fractionated on preparative flat-bed isoelectrofocusing gel in the range of pH 2-12. Native FKBP-25 and its truncated forms were found among other proteins retained on CM52-cellulose. Immunoblotting with anti-FKBP-25 showed two bands in the range 27-30 kDa, one due to unmodified FKBP-25 and other due to FKBP-25 mixed with high-mobility group II protein (HMG-II). Selective immunostaining with anti-FKBP-25 antibodies of proteins which were not retained on CM52-cellulose showed several bands within the range of pI 7-5 and mass of 23 +/- 2 kDa. These fractions of proteins were next resolved on two-dimensional gels and immunostained with anti-FKBP-25 antibodies. Six proteins in the pI range 7-5 were detected. Edman degradation of alpha-chymotrypsin digests of the major spot suggests that it contains the GTP-binding protein Rab5 co-migrating with guanylyl kinase, whereas MALDI-TOF showed that a residual content of FKBP-25 may be also associated with these two proteins. A residual quantity of FKBP-25 was also associated with the phosphatidylethanolamine-binding protein which is abundant in the brain.
Leclercq
M
M
Département d'Ingénierie et d'Etudes des Protéines, CE-Saclay, Gif-sur-Yvette Cedex, 91191, France.
Vinci
F
F
Galat
A
A
D000469:Alkaline Phosphatase / Q000378:metabolism; D000595:Amino Acid Sequence; D000727:Androgen-Binding Protein; D000818:Animals; D015153:Blotting, Western; D001923:Brain Chemistry; D002352:Carrier Proteins / Q000378:metabolism; D002850:Chromatography, Gel; D002918:Chymotrypsin / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D006147:Guanine / Q000378:metabolism; D006609:High Mobility Group Proteins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D015151:Immunoblotting; D020104:Immunophilins / Q000737:chemistry*; D007525:Isoelectric Focusing; D008969:Molecular Sequence Data; D049294:Phospholipid Transfer Proteins; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013552:Swine; D022021:Tacrolimus Binding Proteins; D020696:rab5 GTP-Binding Proteins / Q000378:metabolism
D000727:Androgen-Binding Protein; D002352:Carrier Proteins; D006609:High Mobility Group Proteins; D049294:Phospholipid Transfer Proteins; D020033:Protein Isoforms; D006147:Guanine; D010770:Phosphotransferases; D000469:Alkaline Phosphatase; D002918:Chymotrypsin; C117608:alpha-chymotrypsin; D020696:rab5 GTP-Binding Proteins; D022021:Tacrolimus Binding Proteins; D020104:Immunophilins