A rapid two-step purification of rat cystatin C, one major inhibitor of cysteine proteinases.
Rat cystatin C was purified to apparent homogeneity from rat urine after induction of a tubular dysfunction with sodium chromate. Twentyfold concentrated urine was chromatographed by a rapid purification procedure. A two-step purification including affinity chromatography on carboxymethyl papain- Sepharose and high-resolution anion exchange chromatography was developed. The purified protein has an apparent molecular mass of 15 kDa and pI of 10.2; its aminoacid composition was similar to human cystatin C. As opposed to previous data, purified urinary rat cystatin C did not contain significant amounts of carbohydrate. Antisera against rat cystatin C, raised in rabbits, partially cross-reacted with human and mouse cystatin C, indicating their antigenic similarities. Like human cystatin C, native rat cystatin C, named slow form, is degraded into a more acidic form, called fast form, by a loss of N-terminal amino acids; fast form displayed a pI of 9.4.
Tavera
C
C
INSERM U 133, Faculté de Médecine, Toulouse.
Guillemot
J C
JC
Capdevielle
J
J
Ferrara
P
P
Leung-Tack
J
J
Collé
A
A
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D055316:Cystatin C; D015891:Cystatins / Q000032:analysis / Q000302:isolation & purification* / Q000494:pharmacology / Q000652:urine; D015853:Cysteine Proteinase Inhibitors; D006801:Humans; D007526:Isoelectric Point; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D051381:Rats; D011919:Rats, Inbred Strains; D012689:Sequence Homology, Nucleic Acid
D000596:Amino Acids; C525030:CST3 protein, human; D002241:Carbohydrates; C525031:Cst3 protein, mouse; C525032:Cst3 protein, rat; D055316:Cystatin C; D015891:Cystatins; D015853:Cysteine Proteinase Inhibitors