Full activation without calmodulin of calmodulin-dependent cyclic nucleotide phosphodiesterase by acidic glycosphingolipids: GM3, sialosylneolactotetraosylceramide and sulfatide.
Among calmodulin-non-binding glycosphingolipids, GM3, sialosylneolactotetraosylceramide (LM1), and sulfatide potently activated calmodulin-dependent cyclic nucleotide phosphodiesterase with or without Ca2+ showing ED50 1-5 microM. In contrast to calmodulin-binding gangliosides, these glycosphingolipids activated the enzyme up to the maximum level achieved by Ca2+/calmodulin and did not inhibit the activity at higher concentrations. Competition studies with GD1b that bind both to calmodulin and the enzyme suggest that the calmodulin-non-binding glycosphingolipids activate the enzyme through interaction with the same site of the enzyme as GD1b interacts.
Higashi
H
H
Laboratory of Glycoconjugate Research, Mitsubishi Kasei Institute of Life Sciences, Tokyo, Japan.
Yamagata
T
T
D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases / Q000187:drug effects* / Q000378:metabolism*; D002147:Calmodulin / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D005679:G(M3) Ganglioside / Q000494:pharmacology; D005732:Gangliosides / Q000494:pharmacology; D005915:Globosides / Q000494:pharmacology; D006028:Glycosphingolipids / Q000494:pharmacology*; D008969:Molecular Sequence Data; D013433:Sulfoglycosphingolipids / Q000494:pharmacology
D002147:Calmodulin; D005679:G(M3) Ganglioside; D005732:Gangliosides; D005915:Globosides; D006028:Glycosphingolipids; D013433:Sulfoglycosphingolipids; C033851:ganglioside, GD1b; C037790:sialosylgloboside; D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases