The distribution of collagen:glucosyltransferase in human blood cells and plasma.
Collagen:glucosyltransferase (UDP-glucose:5-hydroxylysine-collagen glucosyltransferase, EC 2.4.1.66) present in platelets, plasma, granulocytes and lymphocytes has been compared in order to determine whether the platelet enzyme has unique properties or distribution which would support a possible role in platelet-collagen interaction. The enzyme was purified 5400-fold from human plasma and 4400 from human platelets. The two enzymes were similar in terms of Km values for reacting with galactosylhydroxylysine (2.75 mM) and UDPglucose (7.4 microM), optimal Mn2+ concentration (10--15 mM) and pH optimum (7.0). The enzyme was not detectable in red cells. As in platelets, the enzyme was detected in membrane-bound and soluble forms in lymphocytes and granulocytes. Identical mobilities were obtained after elution following polyacrylamide gel electrophoresis of the enzymes from plasma, platelets, granulocytes and lymphocytes. These studies do not support a unique role for the collagen:glucosyltransferase of platelets in platelet-collagen interaction.
D001792:Blood Platelets / Q000201:enzymology; D002462:Cell Membrane / Q000201:enzymology; D002469:Cell Separation; D003094:Collagen; D004910:Erythrocyte Membrane / Q000201:enzymology; D004912:Erythrocytes / Q000201:enzymology*; D005964:Glucosyltransferases / Q000097:blood* / Q000302:isolation & purification; D006098:Granulocytes / Q000201:enzymology; D006801:Humans; D008214:Lymphocytes / Q000201:enzymology; D010949:Plasma / Q000201:enzymology*
D003094:Collagen; D005964:Glucosyltransferases; C023247:UDP glucose-collagen glucosyltransferase