title: The small subunit of Hemilipin2, a new heterodimeric phospholipase A2 from Hemiscorpius lepturus scorpion venom, mediates the antiangiogenic effect of the whole protein.
abstract: In a previous study, we reported the identification of Hemilipin, the first secreted heterodimeric phospholipase A2 (sPLA2) from Hemiscorpius lepturus scorpion venom and demonstrated its effective inhibition of all angiogenesis key steps in vitro and in vivo. Here, we aimed to characterize a second sPLA2, Hemilipin2, from the same venom and to elucidate its antiangiogenic effect. The protein was purified by chromatography separation and analyzed by MALDI/TOF mass spectrometry. Its N terminal amino acid sequence was determined by Edman degradation method and the enzymatic activity by fatty acids release assay. Hemilipin2 antiangiogenic activity was investigated by studying its effect in vitro on adhesion, migration and capillary like tube formation of Human Umbilical Vein Endothelial Cells (HUVECs) and Human Pulmonary Artery Endothelial Cells (HPAECs); and in vivo on the chick embryo chorioallantoic membrane (CAM) assay. Data to be presented show that Hemilipin2 is heterodimeric composed by two subunits: the large one has a molecular weight of 12,866 and the small one of 2461 a.m.u. It has a strong calcium-dependent PLA2 activity and impacts angiogenesis in vitro and in vivo without showing any cytotoxic or apoptotic signs. Its chemical modification with p-Bromophenacyl Bromide abolishes the enzymatic activity without affecting the antiangiogenic effect. Furthermore, it has been proved that Hemilipin2 small subunit was able to inhibit blood vessel formation both in vitro and in vivo. These findings may serve as a starting point for the designing of a new generation of specific inhibitor of human angiogenesis at different steps.
authors.affiliation: Carthage University, Sciences Faculty of Bizerte, Jarzouna 7021, Bizerte, Tunisia; Université de Tunis El Manar, Institut Pasteur de Tunis, Laboratoire des Venins et Biomolécules Thérapeutiques LR11IPT08, 13 Place Pasteur, BP 74, Tunis, 1002, Tunisia.
authors.forename: Imen
authors.initials: I
authors.lastname: Jridi
authors.affiliation: Department of Biomedical Sciences and Human Oncology, Section of Internal Medicine and Clinical Oncology, University of Bari Medical School, "Aldo Moro" Piazza Giulio Cesare11, I-70124, Bari, Italy.
authors.forename: Ivana
authors.initials: I
authors.lastname: Catacchio
authors.affiliation: USCR Protein Sequencer, Faculty of Sciences de Sfax, Route de la Soukra km 4, B.P 802, Sfax 3038, Tunisia.
authors.forename: Hafed
authors.initials: H
authors.lastname: Majdoub
authors.affiliation: Pasteur Institute of Iran, Biotechnology Research Center, Medical Biotechnology Department, Venomics Lab, P.O.Box 131649, Tehran 43551, Iran.
authors.forename: Delavar
authors.initials: D
authors.lastname: Shahbazzadeh
authors.affiliation: Université de Tunis El Manar, Institut Pasteur de Tunis, Laboratoire des Venins et Biomolécules Thérapeutiques LR11IPT08, 13 Place Pasteur, BP 74, Tunis, 1002, Tunisia.
authors.forename: Mohamed
authors.initials: M
authors.lastname: El Ayeb
authors.affiliation: Department of Biomedical Sciences and Human Oncology, Section of Clinical Pathology, University of Bari Medical School "Aldo Moro", Piazza Giulio Cesare11, I-70124, Bari, Italy.
authors.forename: Maria Antonia
authors.initials: MA
authors.lastname: Frassanito
authors.affiliation: Department of Biomedical Sciences and Human Oncology, Section of Internal Medicine and Clinical Oncology, University of Bari Medical School, "Aldo Moro" Piazza Giulio Cesare11, I-70124, Bari, Italy.
authors.forename: Antonio Giovanni
authors.initials: AG
authors.lastname: Solimando
authors.affiliation: Department of Basic Medical Sciences, Neurosciences and Sensory Organs Section of Human Anatomy and Histology, University of Bari Medical School "Aldo Moro", National Cancer Institute "Giovanni Paolo II", I-70124 Bari, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Ribatti
authors.affiliation: Department of Biomedical Sciences and Human Oncology, Section of Internal Medicine and Clinical Oncology, University of Bari Medical School, "Aldo Moro" Piazza Giulio Cesare11, I-70124, Bari, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Vacca
authors.affiliation: Université de Tunis El Manar, Institut Pasteur de Tunis, Laboratoire des Venins et Biomolécules Thérapeutiques LR11IPT08, 13 Place Pasteur, BP 74, Tunis, 1002, Tunisia. Electronic address: Lamia.borchani@pasteur.rns.tn.
authors.forename: Lamia
authors.initials: L
authors.lastname: Borchani
mesh_terms: D000098:Acetophenones / Q000737:chemistry; D020533:Angiogenesis Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002642:Chick Embryo; D049033:Chorioallantoic Membrane / Q000187:drug effects; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D054467:Phospholipases A2 / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D021122:Protein Subunits / Q000737:chemistry / Q000494:pharmacology / Q000502:physiology; D012604:Scorpion Venoms / Q000737:chemistry*
chemical_list: D000098:Acetophenones; D020533:Angiogenesis Inhibitors; D021122:Protein Subunits; D012604:Scorpion Venoms; D054467:Phospholipases A2; C006821:4-bromophenacyl bromide
keywords: Angiogenesis; HPAEC; HUVEC; Hemiscorpius lepturus sPLA2 group III; Small subunit