The J Blood-Group Substance of Cattle. J Haptenic Activity of Glycosphingolipids of Serum

Abstract

The bovine J blood-group substance is dissolved in the serum. The total lipids extracted from serum containing the J antigen (termed J+ serum) show haptenic activity in the homologous bovine J system. The total lipids from J-serum, however, show no haptenic activity. The J+ total lipids are, therefore, thought to contain the determinant group of the J antigen.I n fractionation experiments the lipids to be tested were mixed with crude glycerophospholipids extracted from J-serum, since it has been known that auxiliary lipids are required for maximum haptenic effects. The haptenic activity is completely destroyed by periodate oxidation, it does not decrease, however, by deacylation of ester lipids. Various fractionation procedures in addition to deacylation led to a purified glycosphingolipid that proved to be highly active as a J hapten.The low-density lipoproteins prepared from J+ serum as well as the total lipids extracted from these lipoproteins inhibit the hemolysis of J+ erythrocytes in the J system.These results suggest that the J blood-group substance dissolved in bovine J+ serum is a lipoprotein and that its determinant group is a glycosphingolipid.The bovine J blood-group system [1,2] plays a special role among the different blood-group systems of cattle. I n contrast to other blood-group systems the J substance is primarily dissolved I n this paper the serum or erythrocytes containing the J substance are called J f , the serum lacking the J substance is called J-.The J substance corresponds to a naturally occuring antibody (anti-J) that may or may not be found in J-serum. There are differences in the reactibility of the anti-J sera of different animals. Some anti-J sera react more frequently with J+ erythrocytes than others do. Thus. the presence of J subgroups has been suggested. An international terminology of bovine J subgroups, however, has not been intro- duced so far. I n the experiments described in this paper we used J+ serum throughout which has been tested with anti-J sera that had been checked in international comparison tests ; these anti-J sera show the most frequent reactions with J+ erythrocytes. Several years ago we found [5] that the total lipids prepared from J+ serum exhibits haptenic activity in the homologous J system, whereas the corresponding total lipids prepared from J-serum did not exhibit any haptenic activity in the J system. Our previous results have only been described in short communications or abstracts [5-71. This paper presents detailed evidence for the glycosphingolipid nature of the J hapten. MATERIAL AND METHODSBovine J+ and J-sera were obtained from the slaughter-house. The blood-groups had been known prior to the sacrifice of cattle. All experiments described in Results were carried out in duplicates.The various J+ (and J-) serum batches are termed batch I-V. All batches were obtained from one animal each, except batch 11, which was pooled from the blood of several animals. The sera No. 1-111 were kept in a frozen state prior to use, the sera No.IV and V were used f...

Studies on the Attachment of the Bovine J Blood‐Group Substance at the Erythrocyte Membrane

“…It has recently been demonstrated [2] that the J substance dissolved in the serum is a lipoprotein and that the J determinant is a glycosphingolipid.…”

“…The method for this test was essentially the same as described earlier [2] except that a 1.5,/, suspension of test erythrocytes (diluted from an erythrocyte suspension from animals with J substance and of known hematocrit value) was applied and that the results were obtained quantitatively as follows. Generally, 1 mg of the lipid sample (eventually mixed with an appropriate amount of auxiliary lipid as described previously [2]) or a corresponding amount Eur. J. Biochem.…”

“…Auxiliary lipids are usually needed if lipid fractions are to be tested for J activity [2]. They were extracted from lyophilized serum from animals without J substance in large-scale preparations.…”

The J Blood‐Group Substance of Cattle

“…When the J activity was very low, higher sample concentrations were used. Dilution series of these samples were prepared, and the serological tests were carried out as described earlier [4]. A quantitative measurement was achieved by photometric assay of the extent of hemolysis in the individual test tubes [5].…”

“…Recent studies in these laboratories have revealed that the J substance of bovine serum is a lipoprotein, the determinant of which has been found in the glycosphingolipid fraction [4] and that the J activity of bovine erythrocytes is also bound to a lipid [ 5 ] . On the other hand, Uhlenbruck and Schmid [6] found J activity, in addition to a variety of blood-group activities, in mucoproteins prepared by phenol-water extraction from bovine red cells.…”