Identification of a Membrane-Bound, Glycol-Stimulated Phospholipase A2 Located in the Secretory Granules of the Adrenal Medulla

Ellen Hildebrandt, Joseph P. Albanesi

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Chromaffin granule membranes prepared from bovine adrenal medullae showed Ca2+-stimulated phospholipase A2 (PLA2) activity when assayed at pH 9.0 with phosphatidylcholine containing an [14C]-arachidonyl group in the 2-position. However, the activity occurred in both soluble and particulate subcellular fractions, and did not codistribute with markers for the secretory granule. PLA2 activity in the granule membrane preparation was stimulated dramatically by addition of glycerol, ethylene glycol, or poly(ethylene glycol). This glycol-stimulated PLA2 activity codistributed with membrane-bound dopamine β-hydroxylase, a marker for the granule membranes, through the sequence of differential centrifugation steps employed to prepare the granule membrane fraction, as well as on a sucrose density gradient which resolved the granules from mitochondria, lysosomes, and plasma membrane. The glycol-stimulated PLA2 of the chromaffin granule was membrane-bound, exhibited a pH optimum of 7.8, retained activity in the presence of EDTA, and was inactivated by p-bromophenacyl bromide. When different 14C-labeled phospholipids were incorporated into diarachidonylphosphatidylcholine liposomes, 1-palmitoyl-2-arachidonylphosphatidylcholine was a better substrate for this enzyme than 1-palmitoyl-2-oleylphosphatidylcholine or 1-acyl-2-arachidonyl-phosphatidylethanolamine, and distearoylphosphatidylcholine was not hydrolyzed.

Original languageEnglish (US)
Pages (from-to)464-472
Number of pages9
JournalBiochemistry
Volume30
Issue number2
DOIs
StatePublished - Jan 1 1991

Fingerprint

Glycols
Adrenal Medulla
Phospholipases A2
Secretory Vesicles
Membranes
Chromaffin Granules
Ethylene Glycol
Mitochondria
Subcellular Fractions
Centrifugation
Cell membranes
Mixed Function Oxygenases
Lysosomes
Phosphatidylcholines
Edetic Acid
Liposomes
Glycerol
Polyethylene glycols
Sucrose
Dopamine

ASJC Scopus subject areas

  • Biochemistry

Cite this

Identification of a Membrane-Bound, Glycol-Stimulated Phospholipase A2 Located in the Secretory Granules of the Adrenal Medulla. / Hildebrandt, Ellen; Albanesi, Joseph P.

In: Biochemistry, Vol. 30, No. 2, 01.01.1991, p. 464-472.

Research output: Contribution to journalArticle

@article{9b917ce430a34d54b363abdb60f0dbc3,
title = "Identification of a Membrane-Bound, Glycol-Stimulated Phospholipase A2 Located in the Secretory Granules of the Adrenal Medulla",
abstract = "Chromaffin granule membranes prepared from bovine adrenal medullae showed Ca2+-stimulated phospholipase A2 (PLA2) activity when assayed at pH 9.0 with phosphatidylcholine containing an [14C]-arachidonyl group in the 2-position. However, the activity occurred in both soluble and particulate subcellular fractions, and did not codistribute with markers for the secretory granule. PLA2 activity in the granule membrane preparation was stimulated dramatically by addition of glycerol, ethylene glycol, or poly(ethylene glycol). This glycol-stimulated PLA2 activity codistributed with membrane-bound dopamine β-hydroxylase, a marker for the granule membranes, through the sequence of differential centrifugation steps employed to prepare the granule membrane fraction, as well as on a sucrose density gradient which resolved the granules from mitochondria, lysosomes, and plasma membrane. The glycol-stimulated PLA2 of the chromaffin granule was membrane-bound, exhibited a pH optimum of 7.8, retained activity in the presence of EDTA, and was inactivated by p-bromophenacyl bromide. When different 14C-labeled phospholipids were incorporated into diarachidonylphosphatidylcholine liposomes, 1-palmitoyl-2-arachidonylphosphatidylcholine was a better substrate for this enzyme than 1-palmitoyl-2-oleylphosphatidylcholine or 1-acyl-2-arachidonyl-phosphatidylethanolamine, and distearoylphosphatidylcholine was not hydrolyzed.",
author = "Ellen Hildebrandt and Albanesi, {Joseph P.}",
year = "1991",
month = "1",
day = "1",
doi = "10.1021/bi00216a023",
language = "English (US)",
volume = "30",
pages = "464--472",
journal = "Biochemistry",
issn = "0006-2960",
publisher = "American Chemical Society",
number = "2",

}

TY - JOUR

T1 - Identification of a Membrane-Bound, Glycol-Stimulated Phospholipase A2 Located in the Secretory Granules of the Adrenal Medulla

AU - Hildebrandt, Ellen

AU - Albanesi, Joseph P.

PY - 1991/1/1

Y1 - 1991/1/1

N2 - Chromaffin granule membranes prepared from bovine adrenal medullae showed Ca2+-stimulated phospholipase A2 (PLA2) activity when assayed at pH 9.0 with phosphatidylcholine containing an [14C]-arachidonyl group in the 2-position. However, the activity occurred in both soluble and particulate subcellular fractions, and did not codistribute with markers for the secretory granule. PLA2 activity in the granule membrane preparation was stimulated dramatically by addition of glycerol, ethylene glycol, or poly(ethylene glycol). This glycol-stimulated PLA2 activity codistributed with membrane-bound dopamine β-hydroxylase, a marker for the granule membranes, through the sequence of differential centrifugation steps employed to prepare the granule membrane fraction, as well as on a sucrose density gradient which resolved the granules from mitochondria, lysosomes, and plasma membrane. The glycol-stimulated PLA2 of the chromaffin granule was membrane-bound, exhibited a pH optimum of 7.8, retained activity in the presence of EDTA, and was inactivated by p-bromophenacyl bromide. When different 14C-labeled phospholipids were incorporated into diarachidonylphosphatidylcholine liposomes, 1-palmitoyl-2-arachidonylphosphatidylcholine was a better substrate for this enzyme than 1-palmitoyl-2-oleylphosphatidylcholine or 1-acyl-2-arachidonyl-phosphatidylethanolamine, and distearoylphosphatidylcholine was not hydrolyzed.

AB - Chromaffin granule membranes prepared from bovine adrenal medullae showed Ca2+-stimulated phospholipase A2 (PLA2) activity when assayed at pH 9.0 with phosphatidylcholine containing an [14C]-arachidonyl group in the 2-position. However, the activity occurred in both soluble and particulate subcellular fractions, and did not codistribute with markers for the secretory granule. PLA2 activity in the granule membrane preparation was stimulated dramatically by addition of glycerol, ethylene glycol, or poly(ethylene glycol). This glycol-stimulated PLA2 activity codistributed with membrane-bound dopamine β-hydroxylase, a marker for the granule membranes, through the sequence of differential centrifugation steps employed to prepare the granule membrane fraction, as well as on a sucrose density gradient which resolved the granules from mitochondria, lysosomes, and plasma membrane. The glycol-stimulated PLA2 of the chromaffin granule was membrane-bound, exhibited a pH optimum of 7.8, retained activity in the presence of EDTA, and was inactivated by p-bromophenacyl bromide. When different 14C-labeled phospholipids were incorporated into diarachidonylphosphatidylcholine liposomes, 1-palmitoyl-2-arachidonylphosphatidylcholine was a better substrate for this enzyme than 1-palmitoyl-2-oleylphosphatidylcholine or 1-acyl-2-arachidonyl-phosphatidylethanolamine, and distearoylphosphatidylcholine was not hydrolyzed.

UR - http://www.scopus.com/inward/record.url?scp=0026087458&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026087458&partnerID=8YFLogxK

U2 - 10.1021/bi00216a023

DO - 10.1021/bi00216a023

M3 - Article

C2 - 1899026

AN - SCOPUS:0026087458

VL - 30

SP - 464

EP - 472

JO - Biochemistry

JF - Biochemistry

SN - 0006-2960

IS - 2

ER -