Changes in PLA(2) activity after interacting with anti-inflammatory drugs and model membranes: evidence for the involvement of tryptophan residues

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Diana Gaspar (Author) Other; Marlene Lucio (Author) FEUP; Sandra Rocha (Author) Other; Costa L F C Lima (Author) FFUP; Salette Reis (Author) FFUP

Journal

Title: Chemistry and Physics of Lipids

Vol. 164 No. 4

Pages: 292-299

ISSN: 0009-3084

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 12 Citations

Scopus - 14 Citations

Scientific classification

FOS: Natural sciences > Biological sciences

CORDIS: Physical sciences > Chemistry > Analytical chemistry

Other information

Authenticus ID: P-002-RNH

DOI: 10.1016/j.chemphyslip.2011.03.003

Resumo (PT): Phospholipase A2 (PLA2) lipolytic activity can be regarded as a limiting factor for the development of inflammatory processes by restricting the production of pro-inflammatory mediators, hence representing a valuable therapeutic target for drugs that are able to modulate the activity of this enzyme. In the current work, the hydrolysis of phospholipids by PLA2 was monitored with acrylodan-labelled intestinal fatty acid binding protein (ADIFAB) and this fluorescence based technique was also used to access the enzymatic inhibitory effect of non-steroidal anti-inflammatory drugs (NSAIDs). The intrinsic fluorescence of PLA2 tryptophan residues was further used to gain complementary information regarding the accessibility of these residues on the PLA2 structure upon interaction with the NSAIDs tested; and to calculate the NSAIDs-PLA2 binding constants. Finally, circular dichroism (CD) measurements were performed to evaluate changes in PLA2 conformation resultant from the inhibitory effect of the drugs tested. Overall, results gathered in this study point to the conclusion that the studied NSAIDs inhibit PLA2 activity due to a disturbance of the enzyme binding efficiency to membrane interface possibly by a shielding effect of the Trp residues required for the membrane interfacial binding step that precedes lipolysis process. Highlights ► NSAIDs promoted distinct inhibitory effects of PLA2. ► Meloxicam, nimesulide and lornoxicam inhibit PLA2 by shielding the Trp residues and reducing PLA2 flexibility, both mechanisms concurring for the enzyme inhibition. ► Tenoxicam does not reduce PLA2 flexibility, but shields Trp residues that become less available to take part in the enzyme interfacial activation. <br> <br> Keywords: Liposomes; NSAIDs; PLA2 inhibition; ADIFAB; Tryptophan fluorescence quenching and circular dichroism <br> <a target="_blank" href="http://www.sciencedirect.com/science/article/pii/S0009308411000363 "> Texto integral </a> <br> <br>

Abstract (EN): Phospholipase A(2) (PLA(2)) lipolytic activity can be regarded as a limiting factor for the development of inflammatory processes by restricting the production of pro-inflammatory mediators, hence representing a valuable therapeutic target for drugs that are able to modulate the activity of this enzyme. In the current work, the hydrolysis of phospholipids by PLA(2) was monitored with acrylodan-labelled intestinal fatty acid binding protein (ADIFAB) and this fluorescence based technique was also used to access the enzymatic inhibitory effect of non-steroidal anti-inflammatory drugs (NSAIDs). The intrinsic fluorescence of PLA(2) tryptophan residues was further used to gain complementary information regarding the accessibility of these residues on the PLA(2) structure upon interaction with the NSAIDs tested; and to calculate the NSAIDs-PLA(2) binding constants. Finally, circular dichroism (CD) measurements were performed to evaluate changes in PLA(2) conformation resultant from the inhibitory effect of the drugs tested. Overall, results gathered in this study point to the conclusion that the studied NSAIDs inhibit PLA(2) activity due to a disturbance of the enzyme binding efficiency to membrane interface possibly by a shielding effect of the Trp residues required for the membrane interfacial binding step that precedes lipolysis process.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8