Macrophage Ecto-Enzymes: Their Identification, Metabolism, and Control
Ecto-enzymes are enzymes which are associated with the plasma membrane in such a way that their active sites are accessible to the external environment. They are special examples of a more general class of proteins which are associated with the outer face of the plasma membrane and which may be called ‘ecto-proteins’. These proteins are operationally recognized in a variety of ways (Table 1), either because they act as binding sites or receptors for various ligands, because they express enzymatic activity, or because an antibody has been prepared to which they bind. An association of a number of enzymes with the plasma membrane of phagocytes has been established (Table 2) and several of them have been identified as ecto-enzymes by the use of some of the techniques listed in Table 3.
KeywordsDiazonium Salt Outer Face Mouse Peritoneal Macrophage Sulfanilic Acid Nucleotidase Activity
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- DePierre, J.W. & M.L. Karnovsky (1974a) Ecto-enzymes of the guinea pig polymorphonuclear leukocyte. I. Evidence for an ecto-adenosine mono-phosphatase,-adenosine triphosphatase, and-p-nitrophenylphosphate. Journal of Biological Chemistry 249, 7111.Google Scholar
- DePierre, J.W. & M.L. Karnovsky (1974b) Ecto-enzymes of the guinea pig polymorphonuclear leukocyte. II. Properties and suitability as markers for the plasma membrane. Journal of Biological Chemistry 249, 7121.Google Scholar
- Gordon, S., Unkeless, J.C. & Z.A. Cohn (1975) The macrophage as secretory cell. In: immunologic Recognition, A.S. Rosenthal (ed.), p. 589. Academic Press, New York.Google Scholar
- Wang, P., Shirley, P.S., Dechatelet, L.R., McCall, C.E. & B.M. Waite (1976) Purification of plasma membrane from BCG-induced rabbit alveolar macrophages. Journal of the Reticuloendothelial Society 19, 332.Google Scholar
- Werb, Z., & Z.A. Cohn (1972) Plasma membrane synthesis in the macrophage following phagocytosis of polystyrene latex particles. Journal Biological Chemistry247, 2439.Google Scholar