Study for venomous sea anemones inhabiting the coastal areas of Okinawa, Japan

2007 Fiscal Year Final Research Report Summary

• Project/Area Number: 18590403
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Parasitology (including Sanitary zoology)
• Research Institution: University of the Ryukyus
• Principal Investigator: TOMA Hiromu University of the Ryukyus, Faculty of Medicine, Associate Professor (80231447)
• Co-Investigator(Kenkyū-buntansha): UEZATO Hiroshi University of the Ryukyus, Faculty of Medicine, Professor (60160157)
• Project Period (FY): 2006 – 2007
• Keywords: Sea anemone / Hemolysin / Toxin / Health damage / 溶血活性

Research Abstract

Venomous sea anemones Actineria were recently found inhabiting the coastal areas of Okinawa, Japan. The marine animals produce various proteinous toxins, so that a local health organization was called for medical treatment for those who had accidental contact with the animals. In this study we analyzed the biochemical and physiological properties of hemolytic protein from A. villosa. The toxin purified from the tentacles of the animals was found to be a protein with a molecular weight of approximately 19kDa. We named this newly found hemolytic toxin of A. villosa, Avt-I. Incubation of the toxin with sphingomyelin inhabited hemolytic activity by up to 85%, showing that Avt-I may target sphingomyelin on the erythrocyte membrane. The hemolytic activity was stably maintained at temperatures below 45℃, however, a sharp linear decrease in heat stability was observed within the range of 45-55℃. Our results provide the first evidence that A. villosa produces a toxin with strong hemolytic activity similar in biochemical and physiological properties to other members of actinoporin family previously isolated from related species of sea anemones.