Changes in PLA2 activity after interacting with anti-inflammatory drugs and model membranes: evidence for the involvement of tryptophan residues

► 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.