Phosphatidylcholine enhances the activity of rat liver type II phosphatidylinositol-kinase

Summary, in English

A PtdIns 4-kinase was purified extensively from rat liver exocytotic vesicles. The enzyme had a low Km for ATP, was inhibited by adenosine, and had an apparent molecular mass of 54 kDa, indicating it to be a type II PtdIns-kinase. The activity of the purified enzyme was enhanced several-fold by PtdCho, and to some extent by other phospholipids with basic polar head groups, and was inhibited by PtdSer. Kinetic analyses, presenting the substrate in mixed micelles of Triton X-100, PtdIns and PtdCho, showed that the effect of PtdCho was both to increase Vmax and to decrease the apparent Km for micellar PtdIns.

• Author: H Olsson; Wilma Martinez Arias; Bengt Jergil
• Department/s: Department of Experimental Medical Science; Biochemistry and Structural Biology
• Publishing year: 1993
• Language: English
• Pages: 6-332
• Publication/Series: FEBS Letters
• Volume: 327
• Issue: 3
• Links: http://www.ncbi.nlm.nih.gov/pubmed/8394247; http://dx.doi.org/10.1016/0014-5793(93)81015-R
• Document type: Journal article
• Publisher: Wiley-Blackwell
• Topic: Basic Medicine
• Keywords: GelEnzyme ActivationExocytosisLiver/enzymology*MicellesPhosphatidylcholines/pharmacology*Phospholipids/pharmacologyPhosphotransferases/isolation & purificationPhosphotransferases/metabolism*Rats; 1-Phosphatidylinositol 4-KinaseAnimalsChromatography
• Status: Published
• ISBN/ISSN/Other: ISSN: 1873-3468