Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1987 Jun 15;244(3):497-502.
doi: 10.1042/bj2440497.

The effect of sn-2 fatty acid substitution on phospholipase C enzyme activities

J S Bomalaski  1 , M A Clark
Affiliations

The effect of sn-2 fatty acid substitution on phospholipase C enzyme activities

J S Bomalaski et al. Biochem J. .

Abstract

The human monocyte cell line U937 expresses phospholipase A2 and phospholipase C activities and produces eicosanoids. The phospholipase C (PLC) activity exhibits substrate preference for phosphatidyl-choline (PC), rather than phosphatidylinositol or phosphatidylethanolamine. In order to characterize the PLC activity found in these cells, the effects of substitution of the sn-2 fatty acid on this activity were examined. PC substrates with palmitic acid (PC-2P), oleic acid (PC-2O), arachidonic acid (PC-2A) and linoleic acid (PC-2L) at the sn-2 position were used. The sn-1 fatty acid was palmitic acid. PC-2L and PC-2A with the longer-chain less-saturated fatty acids linoleic acid and arachidonic acid esterified at sn-2 were found to be better substrates for PLC activity than PC-2P or PC-2O in these cells. This preference was maintained even when substrate phospholipid was solubilized in non-ionic, anionic, cationic and zwitterionic amphiphiles. Furthermore, when a 500-fold excess of 1,2-diolein or 1,2-dipalmitin was added to the reaction, the specificity of the PLC activity for PC-2A and PC-2L remained unchanged. When similar experiments were performed with phosphatidylinositol as a substrate, we did not observe any effect when the sn-2 position was altered. These data show that the fatty acid constituent at the sn-2 position affects the observed PLC activity when phosphatidylcholine, but not phosphatidylinositol, is used as a substrate by these cells.

PubMed Disclaimer

References

    1. Biochem J. 1983 Nov 1;215(2):325-34 - PubMed
    1. J Exp Med. 1983 Aug 1;158(2):393-412 - PubMed
    1. Biochim Biophys Acta. 1984 Feb 9;792(2):199-206 - PubMed
    1. Biochim Biophys Acta. 1984 Mar 27;793(1):10-7 - PubMed
    1. Biochem J. 1984 Aug 1;221(3):813-20 - PubMed

Publication types