菊黄东方鲀卵黄蛋白原肽段vWD的真核重组表达及功能研究

河鲀的卵黄蛋白原可能参与河豚毒素（TTX）的体内转运过程。为了探讨该机理,建立了毕赤酵母真核表达系统,成功地表达了菊黄东方鲀（Takifugu flavidus）卵黄蛋白原的vWD结构域肽段（rTF_vWD）,并采用Biacore-表面等离子体共振（SPR）系统检测了rTF_vWD与TTX的亲和力,以及腹腔注射小鼠验证rTF_vWD对TTX毒力的中和作用。结果表明:rTF_vWD与TTX的平衡解离常数（KD）为3.1 mmol/L;将TTX与rTF_vWD共孵后肌肉注射小鼠,2 h内小鼠的死亡率显著下降,表明TTX与rTF_vWD结合后,TTX的毒性降低了。     

河豚毒素细菌合成实验方法研究

利用从河豚体内分离得到的细菌Vibrio alginoliticus生产河豚毒素,对发酵条件进行调整,最大化河豚毒素的生产。结果显示,河豚鱼肠与皮肤的提取溶液在一定情况下都能使细菌的适应期缩短,使细菌提早进入指数增长期并有效增加其生物量。     

河豚毒素的提取研究

从福建省泉州市崇武海域的现有资源出发,就河豚鱼的种类,及其毒性,毒素的形成,变化等情况。对河豚毒毒进行提取。纯化,并对毒力进行定量试验研究。结果表明：崇武海域的河豚鱼属于弓斑园豚,其内脏的毒性大小依次为卵、肝和肠。     

Sodium current of neurosecretory cells in the eyestalk from the shrimp Penaeus japonicus

The properties of the inward current of medulla terminalis-X-organ (MTXO) cells isolated from the Penaeus japonicus eyestalk were studied with the whole-cell clamp technique in the presence of Ca²⁺ and K⁺ channel blockers. The inward currents had a threshold at about −50 mV and peaked at −10 mV. The reversed potential (V_rev) was very close to V_Na, the theoretical Nernst equilibrium potential for Na⁺. V_rev followed V_Na when the external Na⁺ concentration was varied and the currents were entirely suppressed by 30 nM tetrodotoxin (TTX), indicating that it was carried by Na⁺. The smooth line of concentration-dependent inhibition of sodium currents by TTX represented the best fit with the Hill equation, yielding an IC₅₀ of 2.1 ± 0.1 nM. The values of the half-maximal activation voltage V_h were −20.6 ± 0.5 and −19.3 ± 0.5 mV, respectively, in the absence and presence of 2 nM TTX. TTX had no significant effect on the voltage dependence of steady-state activation and inactivation of I_Na. Taken together, the results suggest that the inward current recorded under our experimental conditions was carried by sodium ions flowing through fast voltage-dependent Na⁺ channels.     

雷氏大疣蛛粗毒对DRG细胞上钠钾钙离子通道的影响

采用全细胞记录( whole-cell recording)模式膜片钳技术在大鼠背根神经节细胞(dorsal root ganglia,DRG)上检测了雷氏大疣蛛粗毒对电压门控钠通道、钾通道及钙通道的影响.结果表明,雷氏大疣蛛粗毒对TTX-R型钠电流、电压门控钾电流以及钙电流均无明显作用,但对TTX-S型钠电流表现出较...     

僵尸之地(下)

我回到酒店房间,等了超过半个小时,莫妮卡才出现……她像一盏泛着清冷寒光的蜡烛般走进房间,拉出把椅子坐下。然后跷起腿,用她那死鱼般的眼睛盯着我:鲍勃先生,是什么风把你吹到海地来了?得了,莫妮卡,你明知道我来是为了什么!怎么样,和我说说唐尼,还有你别具一格的‘僵尸复活秀'……话音未落,莫妮卡突然以瞬息千里的速度跳上桌子,高举匕首朝我的喉咙刺来:你是来搞勒索的!她厉声嘶吼着说:先是唐尼·怀斯偷走了僵尸药,然后你又找上门来,你们这对耍花招的骗子!老天爷,这个女魔头居然反过来控诉我和老唐是坏人。我感到又惊又气,