Purified and cell-bound CD26: enzymatic inhibition, antibody binding profile, and expression on T cells in relation to other surface markers.
The CD26 activation antigen (Ag), which is expressed on a subpopulation of human T cells, has been characterized as dipeptidyl peptidase IV (DPP IV, EC 3.4.14.5). We investigated some molecular and inhibition characteristics as well as the monoclonal antibody (mAb)-binding profile of this molecule purified from human lymphocytes. Among the antibodies we explored, two, anti-BT5/9 and anti-TA5.9, exhibited a high affinity for both purified and cell-bound CD26 Ag. Their significance in the study of immunologic memory and lymphocyte activation is discussed in relation to other markers of lymphocyte activation. Among 4 types of inhibitors studied, Pro-boroPro proved to be the most promising substance for further research on the physiological role of dipeptidyl peptidase IV (CD26).
Scharpe
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S
Laboratorium Medische Biochemie, Universitaire Instelling Antwerpen, Wilrijk.
De Meester
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I
D000911:Antibodies, Monoclonal / Q000276:immunology; D001666:Binding Sites, Antibody; D001896:Boron Compounds / Q000494:pharmacology; D018819:Dipeptidyl Peptidase 4 / Q000276:immunology*; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000037:antagonists & inhibitors* / Q000302:isolation & purification; D004800:Enzymes, Immobilized; D006031:Glycosylation; D006801:Humans; D007525:Isoelectric Focusing; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008213:Lymphocyte Activation; D011759:Pyrrolidines / Q000494:pharmacology; D013601:T-Lymphocytes / Q000201:enzymology* / Q000276:immunology*
D000911:Antibodies, Monoclonal; D001896:Boron Compounds; D004800:Enzymes, Immobilized; D011759:Pyrrolidines; C083014:1-(2-pyrrolidinylcarbonyl)-2-pyrrolidinylboronic acid; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; D018819:Dipeptidyl Peptidase 4