Glycoprotein coat of the TA3 cell. Isolation and partial characterization of a sialic acid containing glycoprotein fraction

Codington, John F.; Sanford, Barbara H.; Jeanloz, Roger W.

doi:10.1021/bi00764a001

Cited by 83 publications

(53 citation statements)

References 22 publications

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“…USA 71 (1974) f--) A sample of the pure enzyme containing 278 ug of protein as estimated by the Lowry procedure (9) was dialyzed extensively against water and lyophilized. Determination of carbohydrate components of the dried powder (335 Mg) was carried out by gasliquid chromatography, as described by Codington et al (19). Small amounts of glucose (0.7%) and xylose (0.2%) may have derived from contaminants in the dialysis tubing.…”

Section: Methodsmentioning

confidence: 99%

Angiotensin-Converting Enzyme from Rabbit Pulmonary Particles

Soffer

Reza

Caldwell

1974

Proc. Natl. Acad. Sci. U.S.A.

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Angiotensin-converting enzyme has been solubilized from rabbit pulmonary particles and purified to homogeneity. The molecular weight of the native enzyme was estimated to be about 136,000 by glycerol gradient centrifugation, and a value of 140,000 was obtained for the reduced denatured protein by disc-gel electrophoresis in the presence of sodium dodecyl sulfate and 2-mercaptoethanol. The enzyme was found to be a glycoprotein with carbihydrate accounting for approximately 16% of its dry weight. The major sugar residues were identified as galactose, N-acetylglucosamine, and mannose, with smaller amounts of fucose and sialic acid. The homogeneous enzyme catalyzed the release of HisLeu from the COOH-terminus of angiotensin I and of Phe-Arg and Ser-Pro from that of bradykinin.The potent vasopressor octapeptide, angiotensin II, is derived by enzymatic cleavage of the COOH-terminal dipeptide HisLeu from angiotensin I, a relatively inactive decapeptide (for a recent review see ref. 1). An activity catalyzing this reaction was first isolated from horse plasma (2). However, subsequent studies on the metabolism of angiotensin I in vivo (3) have suggested that its physiologic conversion occurs in the lung, and is mediated by a particulate enzyme (4) directly accessible to the pulmonary circulation and thought to be a component of the vascular endothelium (5). Peptide inhibitors of this enzyme are known to block the conversion of angiotensin I to angiotensin II in vivo and have been reported to reverse hypertension in certain animal models (6, 7), thus implicating the enzyme as a potential therapeutic target. We have, therefore, purified angiotensin-converting enzyme directly from rabbit pulmonary particles. This report describes some unusual characteristics of the solubilized homogeneous enzyme.

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Section: Methodsmentioning

confidence: 99%

Angiotensin-Converting Enzyme from Rabbit Pulmonary Particles

Soffer

Reza

Caldwell

1974

Proc. Natl. Acad. Sci. U.S.A.

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“…A few glycoproteins consist of >50% O-linked carbohydrate; these include erythrocyte glycophorin (43), platelet GPIb (7), "masking" glycoproteins on certain tumor cells (44,45), and LSGP (leukocyte sialoglycoprotein; 9), a rat T lymphocyte and thymocyte surface component. LSGP may be the counterpart in the rat of gpL115.…”

Section: Defect In Gplil5 In Lymphocytes Of Wiskott-aldrich Syndrome mentioning

confidence: 99%

“…In certain mouse adenocarcinomas a surface sialoglycoprotein with >50% O-linked carbohydrate, referred to as a "masking" glycoprotein, is thought to confer on the cells the capacity to invade allogeneic and xenogeneic hosts (44,45). Similarly, sialidase treatment of mouse lymphoma cells exposes cryptic tumor antigens on glycolipid molecules that are, themselves, devoid of sialic acid (47).…”

Section: Defect In Gplil5 In Lymphocytes Of Wiskott-aldrich Syndrome mentioning

confidence: 99%

Characterization of a human lymphocyte surface sialoglycoprotein that is defective in Wiskott-Aldrich syndrome.

Remold‐O′Donnell¹,

Kenney²,

Parkman³

et al. 1984

The Journal of Experimental Medicine

189

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gpL115 is a lymphocyte surface component that is deficient in patients with the X-chromosome-linked immune deficiency Wiskott-Aldrich syndrome (6). The glycoprotein nature of gpL115 is demonstrated through labeling in carbohydrate moieties by [3H]NaBH4 and its synthesis by lymphocytes through labeling with [35S]methionine. Native gpL115 adheres to wheat germ lectin-Sepharose and sialidase-treated gpL115 does not adhere, indicating that native gpL115 adheres via clusters of sialic acid residues. When tested on peanut lectin, which shows specificity for the disaccharide Gal beta 1-3GalNAc, gpL115 is nonadherent and sialidase-treated gpL115 is adherent, indicating the presence of the sequence sialic acid-Gal beta 1-3GalNAc, which is characteristic for O-linked (mucin-type, acidic-type) carbohydrates. A surface glycoprotein with all the above characteristics was found on the lymphoblastoid cell line CEM. CEM cells were used as immunogen to generate the monoclonal antibody L10, an IgG1, which binds native and sialidase-treated gpL115 . Sialidase-treatment of gpL115 significantly alters its physical properties, reducing its electrophoretic mobility and changing its behavior on isoelectrofocusing. Cumulatively, these findings indicate that gpL115 , like glycophorin of erythrocytes and GPIb of platelets, is a sialoglyco protein with significant quantities of O-linked carbohydrate. On treatment with limiting sialidase concentrations, gpL115 of normal lymphocytes is transformed into a series of partially desialylated species of decreasing electrophoretic mobility. This finding resembles the situation with lymphocytes of some Wiskott-Aldrich syndrome patients. Lymphocytes of eight Wiskott-Aldrich syndrome patients were found to be deficient in 125I-labeled gpL115 . Lymphocytes from three of these patients displayed an abnormal 125I-component of apparent mol wt 135,000.

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“…Most of the work on the glycoprotein itself has been done on fragments released from the cells by proteolysis (Codington ~ al., 1972). The fragments are large (5 x 10 5 daltons) and form long rod-like structures (Slayter and Codington, 1973 (Friberg et al, 1974).…”

Section: Ta3 Mammary Carcinomamentioning

confidence: 99%