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Title: Structure and function of lysosomal ;#8203;phospholipase A2 and ;#8203;lecithin:cholesterol acyltransferase

Authors:
; ; ; ; ;  [1]
  1. (Michigan)
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
OTHER U.S. GOVERNMENTNIHAHA
OSTI Identifier:
1172430
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nat. Commun.; Journal Volume: 6; Journal Issue: 03, 2015
Country of Publication:
United States
Language:
ENGLISH

Citation Formats

Glukhova, Alisa, Hinkovska-Galcheva, Vania, Kelly, Robert, Abe, Akira, Shayman, James A., and Tesmer , John J.G.. Structure and function of lysosomal ;#8203;phospholipase A2 and ;#8203;lecithin:cholesterol acyltransferase. United States: N. p., 2016. Web. doi:10.1038/ncomms7250.
Glukhova, Alisa, Hinkovska-Galcheva, Vania, Kelly, Robert, Abe, Akira, Shayman, James A., & Tesmer , John J.G.. Structure and function of lysosomal ;#8203;phospholipase A2 and ;#8203;lecithin:cholesterol acyltransferase. United States. doi:10.1038/ncomms7250.
Glukhova, Alisa, Hinkovska-Galcheva, Vania, Kelly, Robert, Abe, Akira, Shayman, James A., and Tesmer , John J.G.. 2016. "Structure and function of lysosomal ;#8203;phospholipase A2 and ;#8203;lecithin:cholesterol acyltransferase". United States. doi:10.1038/ncomms7250.
@article{osti_1172430,
title = {Structure and function of lysosomal ;#8203;phospholipase A2 and ;#8203;lecithin:cholesterol acyltransferase},
author = {Glukhova, Alisa and Hinkovska-Galcheva, Vania and Kelly, Robert and Abe, Akira and Shayman, James A. and Tesmer , John J.G.},
abstractNote = {},
doi = {10.1038/ncomms7250},
journal = {Nat. Commun.},
number = 03, 2015,
volume = 6,
place = {United States},
year = 2016,
month = 6
}
  • Lecithin:cholesterol acyltransferase (LCAT) was purified from hog plasma and subsequently reacted with (/sup 3/H)-Diisopropyl fluorophosphate (DFP). The labeled enzyme was digested with pepsin and the peptides separated by high performance liquid chromatography (HPLC). Two radioactive peptides were isolated, subjected to automated amino acid sequencing and yielded the following data: A) Ile-Ser-Leu-Gly-Ala-Pro-Trp-Gly-Gly-Ser, and B) Tyr-Ile-Phe-Asp-x-Gly-Phe-Pro-Tyr-x-Asp-Pro-Val. Both of these sequences represent very highly conserved regions of the enzyme when compared to the sequence of human LCAT. Peptide (A) is considered to represent the catalytic center of LCAT based on comparisons with data reported in the literature.
  • Phospholipase A has been isolated from a crude lysosomal fraction from rat kidney cortex and purified 7600-fold with a recovery of 9.8% of the starting activity. The purified enzyme is a glycoprotein having an isoelectric point of pH 5.4 and an apparent molecular weight of 30,000 by high-pressure liquid chromatography gel permeation. Naturally occurring inhibitors of lysosomal phospholipase A are present in two of the lysosomal-soluble protein fractions obtained in the purification. They inhibit hydrolysis of 1,2-di(1-/sup 14/C)oleoylphosphatidylcholine by purified phospholipase A/sub 1/ with IC/sub 50/ values of 7-11 ..mu..g. The inhibition is abolished by preincubation with trypsin at 37/supmore » 0/C, but preincubation with trypsin at 4/sup 0/C has no effect, providing evidence that the inhibitors are proteins. The results suggest that the activity of lysosomal phospholipase A may be regulated in part by inhibitory proteins. Lysosomal phospholipase A from rat kidney hydrolyzes the sn-1 acyl group of phosphatidylcholine, does not require divalent cations for full activity, and is not inhibited by ethylenediaminetetraacetic acid. It has an acid pH optimum of 3.6-3.8. Neither rho-bromophenacyl bromide, diisopropyl fluorophosphate, nor mercuric ion inhibits phospholipase A/sub 1/. In contrast to rat liver, which has two major isoenzymes of acid phospholipase A/sub 1/, kidney cortex has only one isoenzyme of lysosomal phospholipase A/sub 1/.« less
  • No abstract prepared.
  • Mutants of Arabidopsis thaliana deficient in plastid glycerol-3-phosphate acyltransferase activity have altered chloroplast membrane lipid composition. This caused an increase in the number of regions of appressed membrane per chloroplast and a decrease in the average number of thylakoid membranes in the appressed regions. The net effect was a significant decrease in the ratio of appressed to nonappressed membranes. A comparison of 77 K fluorescence emission spectra of thylakoid membranes from the mutant and wild type indicated that the ultrastructural changes were associated with an altered distribution of excitation energy transfer from antenna chlorophyll to photosystem II and photosystem Imore » in the mutant. The changes in leaf lipid composition did not significantly affect growth or development of the mutant under standard conditions. However, at temperatures above 28{degree}C the mutant grew slightly more rapidly than the wild type, and measurements of temperature-induced fluorescence yield enhancement suggested an increased thermal stability of the photosynthetic apparatus of the mutant. These effects are consistent with other evidence suggesting that membrane lipid composition is an important determinant of chloroplast structure but has relatively minor direct effects on the function of the membrane proteins associated with photosynthetic electron transport.« less