Release of ectoenzymes from small intestine brush border membranes of mice by phospholipases.
This study investigated ectoenzyme release from small intestine brush border membranes (duodenum and jejunum, Preparation A; ileum, Preparation B) of mice by the action of phosphatidylinositol-specific phospholipase C or glycosyl-phosphatidylinositol-specific phospholipase D. Most of the alkaline phosphatase was solubilized from Preparation A, but about 60% was released from Preparation B. As for alkaline phosphodiesterase I activity, 15 and 10% were released from Preparations A and B, respectively. With Preparation B, octylglucoside treatment followed by phosphatidylinositol-specific phospholipase C or glycosyl-phosphatidylinositol-specific phospholipase D completely solubilized the alkaline phosphatase activity. However, this treatment did not change the ratio of release of alkaline phosphodiesterase I from Preparation A or B. These results indicate that the resistance to alkaline phosphatase found in Preparation B is due to hindered accessibility of the bonding splitting by phosphatidylinositol-specific phospholipase C and not to a modified glycosyl-phosphatidylinositolanchor.
Itami
C
C
Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Hyogo, Japan.
Taguchi
R
R
Ikezawa
H
H
Nakabayashi
T
T
D000469:Alkaline Phosphatase / Q000378:metabolism*; D000818:Animals; D001413:Bacillus thuringiensis / Q000201:enzymology; D005960:Glucosides / Q000378:metabolism; D007421:Intestine, Small / Q000201:enzymology*; D051379:Mice; D008871:Microvilli / Q000201:enzymology; D043264:Phosphodiesterase I; D010739:Phospholipase D / Q000378:metabolism*; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D051381:Rats; D012995:Solubility; D013696:Temperature; D010738:Type C Phospholipases / Q000378:metabolism*
D005960:Glucosides; C018619:octyl-beta-D-glucoside; D000469:Alkaline Phosphatase; D010727:Phosphoric Diester Hydrolases; D010738:Type C Phospholipases; D043264:Phosphodiesterase I; D010739:Phospholipase D