Isolation of an acute-phase phosphorylcholine-reactive pentraxin from channel catfish (Ictalurus punctatus).
1. Channel catfish (Ictalurus punctatus) serum contains a protein that precipitates pneumococcal C-polysaccharide (CPS) in a calcium-dependent fashion. 2. The serum titer of this protein follows an acute-phase pattern in catfish injected with turpentine. 3. A non-glycosylated, phosphorylcholine (PC)-reactive protein (PRP) with molecular mass ca 100 kDa, was isolated from channel catfish acute-phase sera by affinity chromatography on PC-Sepharose 4B. 4. Contaminating proteins with molecular masses ca 700 kDa and ca 20 kDa that co-eluted with PRP from PC-Sepharose appear to be aggregated and native low-molecular weight factors (LMFs), respectively. 5. Purified PRP has gamma mobility but in serum samples PRP has gamma-beta mobility. 6. Electron microscopy confirmed that PRP has planar, pentagonal symmetry. 7. The amino terminus of PRP is blocked, but based on comparison of amino-acid compositions channel catfish PRP is clearly similar to human CRP and is most like CRPs from the dogfish (Mustelus canis) and rainbow trout (Oncorhynchus mykiss).
Szalai
A J
AJ
Department of Microbiology, University of Mississippi Medical Center, Jackson 39216-4505.
Norcum
M T
MT
Bly
J E
JE
Clem
L W
LW
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002097:C-Reactive Protein / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D007059:Ictaluridae / Q000097:blood*; D007120:Immunochemistry; D008854:Microscopy, Electron; D011487:Protein Conformation; D013045:Species Specificity
D000596:Amino Acids; D002097:C-Reactive Protein