Differential inhibition of human secretory and cytosolic phospholipase A2

Märki, F; Breitenstein, Werner; Beriger, E.; Bernasconi, R.; Caravatti, Giorgio; Francis, J. E.; Paioni, R.; Wehrli, H.; Wiederkehr, R.

doi:10.1007/bf01976212

Cited by 18 publications

(8 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Crystallographic experiments on porcine pancreatic type I PLA 2 showed that a free ␣-amino group is an essential requirement for enzyme activity (15,17,32,33). In type II PLA 2 from C. atrox, strong hydrogen bonding occurs between the NH 2 -terminal ␣-amino group and the side chain of residue 4 with the backbone carbonyls and amides of residues 71 and 73 (25).…”

Section: Discussionmentioning

confidence: 99%

Native Peptide Inhibition

Tseng

Inglis

Scott

1996

Journal of Biological Chemistry

View full text Add to dashboard Cite

The binding of low molecular weight type II phospholipase A 2 (EC 3.1.1.4) to membrane surfaces and hydrolysis of phospholipid are thought to involve the formation of a hydrophobic channel into which a single substrate molecule diffuses before cleavage. The floor and right side of the channel are provided by hydrophobic residues 2, 5, and 9 of an amphipathic amino-terminal helix. The channel is postulated to form via a conformational change in this helix and inward movement of a hydrophobic flap (residue 69 side chain). We show that the amino-terminal tryptic peptide of human type II phospholipase A 2 forms a noncovalent complex with the tryptic peptide from residues 70 -74 of the enzyme. Further, the 70 -74-peptide sequence (FLSYK) dose-dependently inhibits phospholipid hydrolysis in a mixed micelle assay. This native peptide inhibition also occurred with type II enzymes from Crotalus durissus and Crotalus atrox, which have different amino acid sequences at the amino terminus as well as different 70 -74 regions of the molecules. Despite significant conservation of tertiary structure among the enzymes, inhibition by each peptide is specific to the enzyme from which the peptide sequence is derived. We propose that these native peptides inhibit enzyme activity via a sequencespecific, noncovalent interaction with the amino-terminal residues of the enzyme, thereby preventing the conformational change on binding to the micelle interface. These experiments demonstrate a new method for specific inhibition of phospholipase A 2 which, in principle, would be applicable to other biologically active polypeptides and proteins.Secretory phospholipases A 2 (PLA 2 ) 1 are a family of calciumdependent 14-kDa enzymes that catalyze the hydrolysis of the S n 2 fatty acyl ester bond of phospholipids (1). These enzymes, which were first described as components of snake venoms and later in mammals, are classified into two major classes, type I and type II, based on their primary structures. Type I PLA 2 of mammalian origin is mainly found in the pancreas (2), while the type II enzyme is stored in secretory granules in blood platelets, macrophages, and neutrophils (3, 4) and in tissues is localized in mast cells, Paneth cells, and chondrocytes (5, 6). It is also found in fluids derived from patients with inflammatory conditions (7,8) and is induced in several cell types in response to inflammatory stimuli (5). Despite differences in their primary sequences (ϳ30% homology only), crystal structures of PLA 2 from bovine pancreas (type I) and human synovial fluid (type II) are almost superimposable and, not surprisingly, the active sites from both types of enzymes are virtually identical (9). Asp-99 and His-48 form an essential catalytic dyad in the fashion of serine proteases (10). Tyr-52 and Tyr-73 appear to be associated with these two residues via a hydrogen bonding network, but there is evidence (11) that Tyr-52 is not essential for the catalytic reaction.From structure-function studies of type I and II enzymes, the first eight residu...

show abstract

Section: Discussionmentioning

confidence: 99%

Native Peptide Inhibition

Tseng

Inglis

Scott

1996

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…Despite the fact that several inhibitors of cPLA 2 have been discovered, e.g. arachidonyl trifluoromethyl ketone (AACOCF 3 ) ( 1 ) and (S) - N -hexadecylpyrrolidine-2-carboxamide (Wy-48,489) − ( 2 ), no compound has been reported to be undergoing clinical development. Moreover, only a few structure−activity relationship investigations relating to those enzyme inhibitors have been published to date.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Biological Evaluation, and Structure−Activity Relationships of 3-Acylindole-2-carboxylic Acids as Inhibitors of the Cytosolic Phospholipase A₂

Lehr

1997

J. Med. Chem.

View full text Add to dashboard Cite

3-Acylindole-2-carboxylic acid derivatives were prepared and evaluated for their ability to inhibit the cytosolic phospholipase A2 of intact bovine platelets. To define the structural requirements for enzyme inhibition, the carboxylic acid group, the acyl residue, and the moiety in position 1 were systematically modified. Furthermore, different substituents were introduced into the phenyl part of the indole. Replacement of the carboxylic acid group in position 2 of the indole with an acetic or propionic acid substituent led to a decrease of inhibitory potency. Enzyme inhibition was optimal when the acyl residue in position 3 had a length of 12 or more carbons. Conformational restriction of the acyl residue did not influence activity. Introduction of alkyl chains at position 1 of the indole with 8 or more carbons resulted in a loss of activity. However, replacing the omega-methyl group of such compounds with a carboxylic acid moiety was found to increase inhibitory potency significantly. Among the tested indole derivatives, 1-[2-(4-carboxyphenoxy)ethyl]-3-dodecanoylindole-2-carboxyli c acid (29b) had the highest potency. With an IC50 of 0.5 microM it was about 20-fold more active than the standard cPLA2 inhibitor arachidonyl trifluoromethyl ketone (IC50: 11 microM).

show abstract

“…Märki et al [131] reported an IC50 of 15 µM for Wy-48489 against h-cPLA2 isolated from the U937 cell line.…”

Section: Pla2 Inhibitors From Wyeth-ayerstmentioning

confidence: 99%

“…Wy-49422 (oxiranecarboxylic acid, 2-[5-(4-chlorophenyl)pentyl]-ethylester) was also described as an sPLA2 inhibitor [131], and the compound depressed human platelet and synovial sPLA2s with IC50 values of 18 and 36 µM, respectively. Wy-49422 and Wy-48489 were derived from two different structural classes, but both agents were anti-inflammatory in vivo (phorbol ester-induced mouse ear oedema, carrageenan-induced rat paw oedema).…”

Section: Pla2 Inhibitors From Wyeth-ayerstmentioning

confidence: 99%

Phospholipase A2 inhibitors in development

Tibes

1997

Expert Opinion on Investigational Drugs

View full text Add to dashboard Cite

To date, three isoforms of phospholipase A2 (PLA2) have been identified. Of these, the two Ca2+-dependent isoforms, secretory (sPLA2) and cytosolic phospholipase A2 (cPLA2), are targets for new anti-inflammatory drugs. The catalytic mechanisms and functions of the third isoform, Ca2+-independent cytosolic phospholipase A2 (iPLA2), are unknown at present. sPLA2 and cPLA2 are both implicated in the release of arachidonic acid and prophlogistic lipid mediators. However, recent findings provide evidence that cPLA2 is the dominant isoform in various kinds of inflammation, such as T-cell-mediated experimental arthritis. A triple function of PLA2-derived lipid mediators has been suggested: causing immediate inflammatory signs, involvement in secondary processes, e.g., superoxide free radical (O2) generation, apoptosis, or tumour necrosis factor-alpha (TNF-alpha)-cytotoxicity, and controlling the expression and activation of pivotal proteins implicated in inflammation and cell development, e.g., cytokines, adhesion proteins, proteinases, NF-kappaB, fos/jun/AP-1, c-Myc, or p21ras. In the past, research predominantly focused on the development of sPLA2 inhibitors; however, present techniques enable discrimination of cPLA2, sPLA2, and iPLA2, and specific inhibitors of each of the three isoforms are likely to appear soon. Over the last decade, between 40 and 50 sPLA2 inhibitors have been described; and the list is growing. However, of these, few have the potential for clinical success, and those that do are predominantly active site-directed inhibitors, e.g., BMS-181162, LY311727, ARL-67974, FPL67047, SB-203347, Ro-23-9358, YM-26734, and IS-741. At present, there are no likely clinical candidates emerging from the ranks of cPLA2 and iPLA2 inhibitors in development. Indications for which PLA2 inhibitors are being pursued include, sepsis, acute pancreatitis, inflammatory skin and bowel diseases, asthma, and rheumatoid arthritis. The three main obstacles to the successful development of PLA2 inhibitors include, insufficient oral bioavailability, low affinity for the enzyme corresponding to low in vivo efficacy and insufficient selectivity.

show abstract

Differential inhibition of human secretory and cytosolic phospholipase A2

Cited by 18 publications

References 38 publications

Native Peptide Inhibition

Native Peptide Inhibition

Synthesis, Biological Evaluation, and Structure−Activity Relationships of 3-Acylindole-2-carboxylic Acids as Inhibitors of the Cytosolic Phospholipase A₂

Phospholipase A2 inhibitors in development

Contact Info

Product

Resources

About

Differential inhibition of human secretory and cytosolic phospholipase A2

Cited by 18 publications

References 38 publications

Native Peptide Inhibition

Native Peptide Inhibition

Synthesis, Biological Evaluation, and Structure−Activity Relationships of 3-Acylindole-2-carboxylic Acids as Inhibitors of the Cytosolic Phospholipase A2

Phospholipase A2 inhibitors in development

Contact Info

Product

Resources

About

Synthesis, Biological Evaluation, and Structure−Activity Relationships of 3-Acylindole-2-carboxylic Acids as Inhibitors of the Cytosolic Phospholipase A₂