| Title | Membrane-bound conformation and phospholipid components modulate membrane-damaging activity of Taiwan cobra cardiotoxins. | | Author(s) | Kao PH, Lin SR, Wu MJ, Chang LS | | Institution | Institute of Biomedical Sciences, National Sun Yat-Sen University-Kaohsiung Medical University Joint Research Center, National Sun Yat-Sen University, No. 70, Lien-Hai Road, Kaohsiung 804, Taiwan. | | Source | Toxicon 2009 Apr; 53(5):512-8. | | Abstract | Membrane-damaging activity of Naja naja atra cardiotoxin 3 (CTX3) on 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC)/1,2-dimyristoyl-phosphatidic acid (DMPA) vesicles was approximately 3-fold that of N. naja atra cardiotoxin 4 (CTX4), while CTX3 and CTX4 displayed insignificantly permeabilizing activity in 1,2-dipalmitoyl-phosphatidylcholine (DPPC)/DMPA vesicles. Phospholipid-binding capability and oligomeric assembly upon binding with lipid vesicles did not closely correlate with membrane-damaging potency of CTX3 and CTX4. Geometrical arrangement of CTX3 in contact with POPC/DMPA vesicles was different from that noted with CTX4, and binding forces between CTX3 and POPC/DMPA were stronger than those between CTX4 and POPC/DMPA. Unlike POPC/DMPA, the interaction between CTXs and DPPC/DMPA was drastically reduced by increasing salt concentration. Color transformation of phospholipid/polydiacetylene membrane assay and FTIR spectra analyses revealed that CTX3 and CTX4 adopted different conformationsand modes upon absorption on POPC/DMPA and DPPC/DMPA vesicles. Taken together, our data show that, in addition to membrane packing density and phospholipid-binding capability, membrane-bound conformation of CTXs plays a vital role in displaying membrane-damaging activity. | | Language | eng | | Pub Type(s) | Journal Article
Research Support, Non-U.S. Gov't
| | PubMed ID | 19673097 |
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