HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wang, J. Articles by Parks, J. S. Search for Related Content PubMed PubMed Citation Articles by Wang, J. Articles by Parks, J. S. Social Bookmarking                      What's this?

Volume 272, Number 1, Issue of January 3, 1997 pp. 280-286
©1997 by The American Society for Biochemistry and Molecular Biology, Inc.

---

Amino Acid Residue 149 of Lecithin:Cholesterol Acyltransferase Determines Phospholipase A₂ and Transacylase Fatty Acyl Specificity

(Received for publication, September 16, 1996, and in revised form, October 22, 1996)

Jingchuan Wang , Abraham K. Gebre , Richard A. Anderson and John S. Parks

From the Departments of Comparative Medicine and  Internal Medicine, The Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, North Carolina 27157

Human LCAT prefers phosphatidylcholine (PC) with sn-1-palmitoyl-2-oleoyl PC (POPC) as substrate for cholesteryl ester synthesis, whereas rat LCAT (which is 92% similar in amino acid sequence) prefers sn-1-palmitoyl-2-arachidonoyl PC (PAPC). Six recombinant human LCAT cDNA clones were constructed with unique clusters of rat sequence substitutions in the human background spanning the region encoding amino acids 121-296. Media from transfected COS cells expressing each of the constructs were assayed for LCAT cholesterol esterification (CE) or phospholipase A₂ (PLA₂) activity using substrate particles containing POPC or PAPC. The PAPC/POPC CE activity ratio of the cluster 1 construct (amino acids 149-158) was 1.3, resembling rat LCAT, whereas cluster 2-5 clones produced CE activity ratios <0.3, unchanged from human LCAT. The cluster 6 clone (Y292H/W294F) had an intermediate ratio (0.6). Similar results were observed for LCAT PLA₂ activity. In additional studies, position 149 of human LCAT was changed to the rat sequence (hE149A) and compared to a triple mutation containing the remainder of the cluster 1 changes (G151R/E154D/R158Q). CE and PLA₂ activity ratio for the hE149A construct was >1.7, similar to rat LCAT, whereas the triple mutation construct retained a ratio similar to human LCAT (<0.6). Thus, a single amino acid substitution (E149A) was sufficient to alter the fatty acyl specificity of human LCAT to that of rat LCAT, with an increase in activity toward PAPC. This is the first example of a point mutation in an enzyme with PLA₂ activity that results in an increase in activity toward arachidonic acid.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				M. Hiraoka, A. Abe, and J. A. Shayman Structure and function of lysosomal phospholipase A2: identification of the catalytic triad and the role of cysteine residues J. Lipid Res., November 1, 2005; 46(11): 2441 - 2447. [Abstract] [Full Text] [PDF]

				P. Bhanot, K. Schauer, I. Coppens, and V. Nussenzweig A Surface Phospholipase Is Involved in the Migration of Plasmodium Sporozoites through Cells J. Biol. Chem., February 25, 2005; 280(8): 6752 - 6760. [Abstract] [Full Text] [PDF]

				Y. Zhao, A. K. Gebre, and J. S. Parks Amino acids 149 and 294 of human lecithin:cholesterol acyltransferase affect fatty acyl specificity J. Lipid Res., December 1, 2004; 45(12): 2310 - 2316. [Abstract] [Full Text] [PDF]

				U. Stahl, A. S. Carlsson, M. Lenman, A. Dahlqvist, B. Huang, W. Banas, A. Banas, and S. Stymne Cloning and Functional Characterization of a Phospholipid:Diacylglycerol Acyltransferase from Arabidopsis Plant Physiology, July 1, 2004; 135(3): 1324 - 1335. [Abstract] [Full Text] [PDF]

				L. Zhou and A. Nilsson Sources of eicosanoid precursor fatty acid pools in tissues J. Lipid Res., October 1, 2001; 42(10): 1521 - 1542. [Abstract] [Full Text] [PDF]

				J. W. Furbee Jr., O. Francone, and J. S. Parks Alteration of plasma HDL cholesteryl ester composition with transgenic expression of a point mutation (E149A) of human LCAT J. Lipid Res., October 1, 2001; 42(10): 1626 - 1635. [Abstract] [Full Text] [PDF]

				K.-A. Rye and M. N. Duong Influence of phospholipid depletion on the size, structure, and remodeling of reconstituted high density lipoproteins J. Lipid Res., October 1, 2000; 41(10): 1640 - 1650. [Abstract] [Full Text]

				J. S. Parks, K. W. Huggins, A. K. Gebre, and E. R. Burleson Phosphatidylcholine fluidity and structure affect lecithin:cholesterol acyltransferase activity J. Lipid Res., April 1, 2000; 41(4): 546 - 553. [Abstract] [Full Text]

				F. Peelman, J-L. Verschelde, B. Vanloo, C. Ampe, C. Labeur, J. Tavernier, J. Vandekerckhove, and M. Rosseneu Effects of natural mutations in lecithin:cholesterol acyltransferase on the enzyme structure and activity J. Lipid Res., January 1, 1999; 40(1): 59 - 69. [Abstract] [Full Text]

				S. Adimoolam, L. Jin, E. Grabbe, J.-J. Shieh, and A. Jonas Structural and Functional Properties of Two Mutants of Lecithin-Cholesterol Acyltransferase (T123I and N228K) J. Biol. Chem., December 4, 1998; 273(49): 32561 - 32567. [Abstract] [Full Text] [PDF]

				J. Wang, J. A. DeLozier, A. K. Gebre, P. J. Dolphin, and J. S. Parks Role of glutamic acid residues 154, 155, and 165 of lecithin:cholesterol acyltransferase in cholesterol esterification and phospholipase A2 activities J. Lipid Res., January 1, 1998; 39(1): 51 - 58. [Abstract] [Full Text]