Concerted Modulation by Myelin Basic Protein and Sulfatide of the Activity of Phospholipase A2 against Phospholipid Monolayers

Ismael D. Bianco, Gerardo D. Fidelio, Robert K. Yu, Bruno Maggio

Research output: Contribution to journalArticle

19 Scopus citations

Abstract

The effect of myelin basic protein (MBP) on the activity of phospholipase A2 (PLA2, EC 3.1.1.4) against monolayers of dilauroylphosphatidylcholine (dlPC) or dilauroylphosphatidic acid (dlPA) containing different proportions of sulfatide (Sulf) and galactocerebroside (GalCer) was investigated. MBP was introduced into the interface by direct spreading as an initial constitutive component of the lipid-protein film or by adsorption and penetration from the subphase into the preformed lipid monolayers. The effect of MBP on PLA2 activity depends on the type of phospholipid and on the proportion of MBP at the interface. At a low mole fraction of MBP, homogeneously mixed lipid-protein monolayers are formed, and the PLA2 activity against dlPC is only slightly modified while the degradation of dlPA is markedly inhibited. This is probably due to favorable charge-charge interactions between dlPA and MBP that interfere with the enzyme action. The PLA2 activity against either phospholipid is increased when the mole fraction of MBP exceeds the proportion at which immiscible surface domains are formed. GalCer has little effect on the modulation by MBP of the phospholipase activity. The effect of Sulf depends on its proportions in relation to MBP. The individual effects of both components balance each other, and a finely tuned modulation is regulated by the interactions of MBP with Sulf or with the phospholipid.

Original languageEnglish (US)
Pages (from-to)2636-2642
Number of pages7
JournalBiochemistry
Volume31
Issue number10
DOIs
StatePublished - Mar 1 1992
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry

Fingerprint Dive into the research topics of 'Concerted Modulation by Myelin Basic Protein and Sulfatide of the Activity of Phospholipase A<sub>2</sub> against Phospholipid Monolayers'. Together they form a unique fingerprint.

  • Cite this