Bovine early pregnancy factor (EPF) activity dependent on a 67-kDa polypeptide.
Maternal bovine EPF activity can be reduced to one single polypeptide enriched and identified from serum of cows in early pregnancy. The relative molecular weight of this active polypeptide was estimated at 67 kDa. This bovine EPF was labelled by 125I and peroxidase. In parallel investigations of non-pregnant animals a 67-kDa polypeptide was additionally identified in the last purification step, but without EPF activity in the rosette inhibition test. This indicated occurrence of an inactive pre-compound (or carrier protein) of the EPF in the non-pregnant state. On pre-incubation of lymphocytes with EPF analogues (inactive polypeptide from nonpregnancy serum) EPF retained its optimal activity, its lymphocyte receptors being unaffected. Monoclonal antibodies produced against HPLC-enriched EPF were reactive to the 67-kDa polypeptide in pregnancy material as well as in nonpregnancy material and were not able to differentiate between 'pregnant' and 'nonpregnant'. A mouse anti-EPF serum produced against highly purified EPF isolated from SDS PAGE showed reactivity only against the 67-kDa polypeptide of pregnancy serum but not against that of non-pregnancy serum. This is the first evidence for a difference in antigenic determinants of the two 67-kDa proteins found in pregnancy and non-pregnancy serum. Furthermore, a second higher molecular weight protein could be identified by this antiserum in pregnancy and non-pregnancy serum.
Klima
F
F
Vertebrate Research Centre, D-(0), Berlin, F.R.G.
Tiemann
U
U
Schadow
D
D
Fasinski
M
M
Savoly
S B
SB
Loose
R
R
Pitra
C
C
D000818:Animals; D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D002417:Cattle; D018835:Chaperonin 10; D005260:Female; D008970:Molecular Weight; D010455:Peptides / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D011270:Pregnancy, Animal / Q000276:immunology*; D011485:Protein Binding; D013491:Suppressor Factors, Immunologic / Q000737:chemistry; D013601:T-Lymphocytes / Q000378:metabolism
D000911:Antibodies, Monoclonal; D018835:Chaperonin 10; D010455:Peptides; D011257:Pregnancy Proteins; D013491:Suppressor Factors, Immunologic; C025124:early pregnancy factor