title: Neutralizing effect of hemolymph from the shore crab, Thalamita crenata, on paralytic shellfish toxins.
abstract: Several species of crabs are resistant to paralytic shellfish toxins (PSTs) and/or pufferfish toxin, tetrodotoxin, regardless of toxification by the toxins. The shore crab Thalamita crenata, which inhabits Leizhou Peninsula, China, is tolerant to PST toxicity, and the hemolymph has neutralizing effects against the lethal activity of PST. In the present study, we investigated the PST neutralizing factors in the hemolymph from T. crenata and successfully separated PST-binding proteins by PST-ligand affinity chromatography. The neutralization factors, obtained in the fraction with a molecular weight over 10 kDa by ultrafiltration, were susceptible to proteases such as alcalase, animal complex proteases, pancreatin, and papain. The PST-binding protein had high dose-dependent neutralization effects on PST toxicity. The PST-binding activity of the protein was stable at 25 °C and then decreased with an increase in temperature; heating at 65 °C for 60 min eliminated the initial activity by two-thirds. The PST-binding activity was strongly inhibited in the presence of Mg(2+) and Ca(2+), but not Na(+) and K(+). The PST-binding capability of the protein differed among PST components in descending order of neosaxitoxin, gonyautoxins 1 and 4, saxitoxin, and gonyautoxins 2 and 3, suggesting a structure-activity relationship in PST binding.
authors: College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China; Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Zhanjian, Gaunadong Province 524088, China. Electronic address: huajuanlin@vip.163.com.
authors: Huajuan
authors: H
authors: Lin
authors: College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China; Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Zhanjian, Gaunadong Province 524088, China. Electronic address: chz2382@126.com.
authors: Chaohua
authors: C
authors: Zhang
authors: Zhanjiang Institute of Supervision & Test on Quality & Measure, Zhanjiang 524096, China. Electronic address: idk123@126.com.
authors: Jianmeng
authors: J
authors: Liao
authors: Zhanjiang Ocean and Fishery Environment Monitor Station, Zhanjiang 524039, China. Electronic address: yangfengde@126.com.
authors: Feng
authors: F
authors: Yang
authors: College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China; Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Zhanjian, Gaunadong Province 524088, China. Electronic address: zsylxc@126.com.
authors: Saiyi
authors: S
authors: Zhong
authors: College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China. Electronic address: jiangpeihongjph@163.com.
authors: Peihong
authors: P
authors: Jiang
authors: College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China. Electronic address: zhihanxiaoxiao@126.com.
authors: Xiao
authors: X
authors: Chen
authors: Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, Minato, Tokyo 108-8477, Japan. Electronic address: yujicd@kaiyodai.ac.jp.
authors: Yuji
authors: Y
authors: Nagashima
mesh_terms: D000818:Animals; D000931:Antidotes / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000627:therapeutic use*; D060829:Arthropod Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000627:therapeutic use*; D001681:Biological Assay; D003386:Brachyura / Q000737:chemistry* / Q000254:growth & development; D002681:China; D002846:Chromatography, Affinity; D004355:Drug Stability; D006458:Hemolymph / Q000737:chemistry*; D006358:Hot Temperature / Q000009:adverse effects; D008024:Ligands; D008297:Male; D008387:Marine Toxins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000633:toxicity; D051379:Mice; D008970:Molecular Weight; D010140:Pacific Ocean; D055550:Protein Stability; D059748:Proteolysis; D012530:Saxitoxin / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000633:toxicity; D057096:Shellfish Poisoning / Q000188:drug therapy* / Q000209:etiology
chemical_list: D000931:Antidotes; D060829:Arthropod Proteins; D008024:Ligands; D008387:Marine Toxins; D012530:Saxitoxin; C034902:neosaxitoxin; C013007:gonyautoxins
keywords: PST-binding protein; PST-ligand affinity chromatography; Paralytic shellfish toxins (PST); Shore crab; Thalamita crenata; Toxicity neutralization