Occurrence of phosphatidyl-D-serine in the rat cerebrum.
Phosphatidylserine (PS), a relatively abundant component of mammalian cell membranes, plays important roles in biological processes including apoptosis and cell signaling. It is believed that phosphatidyl-L-serine is the only naturally occurring PS. Here, we describe for the first time the occurrence of phosphatidyl-D-serine (D-PS) in rat cerebrum. Quantitative HPLC analysis of the derivatives of serine liberated from PS by hydrolysis revealed that the amount of D-PS was approximately 1% of the total PS in the cerebrum. Enzymatic cleavage of cerebrum PS with phospholipase D and phospholipase C resulted in the release of both isomers of serine and phosphoserine, respectively, providing additional evidence for the existence of D-PS. Free D-serine was incorporated into PS in an in vitro system using a cerebrum extract, and this activity was inhibited by EDTA, suggesting the occurrence of a divalent cation-dependent enzyme that synthesizes D-PS by a base-exchange reaction.
Omori
Taketo
T
Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, Japan.
Mihara
Hisaaki
H
Kurihara
Tatsuo
T
Esaki
Nobuyoshi
N
D000818:Animals; D054022:Cerebrum / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D006868:Hydrolysis; D008297:Male; D010718:Phosphatidylserines / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D010739:Phospholipase D / Q000737:chemistry; D051381:Rats; D011919:Rats, Inbred Strains; D010738:Type C Phospholipases / Q000737:chemistry
D010718:Phosphatidylserines; D010738:Type C Phospholipases; D010739:Phospholipase D