Structural Aspects of Heterologous Blood‐Group‐P₁ Substance

Abstract

Blood-group-P, substance from sheep hydatid-cyst fluid was purified by a combination of gel filtration through Sepharose 6B and preparative polyacrylamide-gel electrophoresis. The resultant glycoprotein contained D-galactose ; D-glucose ; N-acetyl-D-ghcosamhe and N-acetyl-D-galactosamine in molar ratios 5.2 : 1 : 2 : 2; unidentified carbohydrate was also present. The amino-acid composition resembled that of vertebrate A, B, H and Lewis active glycoproteins.Prolonged incubation of P, substance with coffee bean ol-galactosidase resulted in the liberation of 17-240/, of the total D-galactose present and a reduction in blood-group-P, inhibitory activity. The serological activity of the glycoprotein was unaffected by treatment with pronase or papain.P, substance has receptors for the agglutinins from Salmo trutta, Clupm harengus, Soja hispida, Maclura aurantiaca and Triticum vulgaris. Some loss of receptor for Soja hispida and Maclura aurantiaca occurred after ol-D-galactosidase treatment.The structural immunochemistry of the P bloodgroup system of human erythrocytes has not yet been elucidated, although, in common with the ABO system, blood-group-active substances of heterologous origin are available and have provided insight into cross-reactive antigens. Cameron and Staveley [I] reported that hydatid-cyst fluid from sheep carrying tapeworm parasites (Echinococcus granulosus) had potent P, inhibitory activity. Freezedried hydatid-cyst fluid was extracted with phenol, by the procedure used to extract blood-group materials from human ovarian-cyst fluid. The resultant glycoprotein was reported to be similar in composition to human ovarian-cyst blood-group substances [2].Serological studies demonstrated strong specific PI inhibitory activity and indicated the importance of a-D-galactosyl groupings in P, blood-group activity We are reporting additional observations relating to the structure and serological characteristics of the P, active glycoprotein. ~31.

Purification and properties of sialoadhesin, a sialic acid-binding receptor of murine tissue macrophages.

“…Free sialic acid, either 35 ,ag membrane protein was loaded on each track and the blots were treated as follows: track 1 was stained with aurodye for total protein; track 2 was treated with periodate followed by peroxidase-hydrazide reagent to reveal glycophorins; tracks 3-5 were labelled with 125I1 sialoadhesin either alone (track 3), following treatment of the blot with neuraminidase (track 4) or in the presence of 20 14g/ml F(ab')2 of the inhibitory antibody 3D6 (track 5). Sialoglycoproteins (SGP) are labelled according to the nomenclature proposed by Anstee (Anstee et al, 1979).…”

“…Sialoadhesin bound to several membrane proteins in a specific and sialic acid-dependent manner (Figure 4, lanes 3-5). Using a peroxidase-hydrazide reagent to detect sialoglycoproteins (Gershoni et al, 1985), all of the recognized bands corresponded to glycophorins, either monomers of glycophorin A and C (a and 1 in Figure 4), homodimers of glycophorins A and B or heterodimers of glycophorins A and B (a2, 62 or ab in Figure 4 respectively) (Anstee et al, 1979). However, bands r (component E) and 6 (monomeric glycophorin B) were apparently not recognized by sialoadhesin under the conditions used.…”

The membrane change in En(a-) human erythrocytes. Absence of the major erythrocyte sialoglycoprotein

“…Achatina granulata (freeze-dried albumin glands) was from Dr. S. Khalap, Metropolitan Police Forensic Science Laboratory, London SE1 7JH, U.K.; 100mg was dissolved in 1 ml of phosphate-buffered saline. The preparation of crude extracts of other lectins used has been described (Anstee & Pardoe, 1973). The lectins from Maclura aurantiaca, Helix pomatia and Triticum vulgaris (wheat-germ agglutinin) were used after purification by absorption and elution from formaldehyde-treated human erythrocytes.…”

Abnormal blood-group-Ss-active sialoglycoproteins in the membrane of Miltenberger class III, IV and V human erythrocytes

“…V erythrocytes SDS/polyacrylamide-gel electrophoresis. Our previous studies on cells heterozygous for the Mi.V condition suggested that these cells contained decreased amounts of component a and increased periodate staining in the region of component f, (Anstee & Tanner, 1978). Further investigation of membranes from these cells has shown that, in addition to the increased staining in the region of component ,B (apparent mol.wt.…”

“…The Mk condition is associated with the loss of MN and Ss antigens and has been shown to be accompanied by the absence of component a (Dahr et al, 1977;Anstee & Tanner, 1978;Furthmayr, 1978). On the basis of decreased periodate/Schiff staining of component in Mk heterozygotes, Dahr et al (1977) concluded that the Mk condition was also associated with the absence of this component.…”