Isolation of a pentraxin-like protein from rainbow trout serum.
Serum amyloid P-component (SAP) is a glycoprotein consisting of five or ten noncovalently associated identical subunits of molecular weight 19,000-30,000. Herein we report the isolation and partial characterization of a SAP-like protein from rainbow trout serum. The protein was isolated by calcium-dependent binding to Sepharose followed by ion-exchange and size-exclusion chromatography. Rabbit antibody against human SAP reacted with the trout protein and the NH2-terminal sequence of 16 amino acids showed 60% identity with the first 15 residues of human SAP. SDS-PAGE and endoglycosidase treatment indicated that the trout protein is a glycoprotein in which five or six subunits are linked by disulphide bonds. The subunits have a molecular weight of 37,000 of which approximately 13% is due to carbohydrate. We propose to name the trout protein sulphide linked SAP (SL-SAP).
Jensen
L E
LE
Department of Medical Microbiology and Immunology, University of Aarhus, Denmark.
Petersen
T E
TE
Thiel
S
S
Jensenius
J C
JC
D000510:Alpha-Globulins / Q000737:chemistry / Q000302:isolation & purification*; D000595:Amino Acid Sequence; D000818:Animals; D002097:C-Reactive Protein / Q000737:chemistry / Q000302:isolation & purification*; D006031:Glycosylation; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017686:Oncorhynchus mykiss / Q000097:blood*; D011485:Protein Binding; D011817:Rabbits; D012685:Sepharose; D017386:Sequence Homology, Amino Acid; D000683:Serum Amyloid P-Component / Q000737:chemistry / Q000302:isolation & purification*
D000510:Alpha-Globulins; D000683:Serum Amyloid P-Component; C030974:female protein, hamster; D002097:C-Reactive Protein; D012685:Sepharose