Vaporization of Inorganic Mercury by Cell-free Extracts of Drug Resistant Escherichia coli

The cDNAs encoding venom phospholipase A₂ (PLA₂) inhibitors (PLIs), named Protobothrops elegans (Pe)γPLI-A, PeγPLI-B, PeαPLI-A, and PeαPLI-B, were cloned from the P. elegans liver cDNA library. They were further divided into several constituents due to nucleotide substitutions in their open reading frames. For PeαPLI-A, two constituents, PeαPLI-A_a and PeαPLI-A_b, were identified due to three nonsynonymous substitutions in exon 3. Far-western blot and mass-spectrometry analysis of the P. elegans serum proteins showed the presence of γPLIs, and αPLIs, which can bind venom PLA₂s. In αPLIs from Protobothrops sera, A or B subtype-specific amino acid substitutions are concentrated only in exon 3. A comparison of γPLIs showed that γPLI-As are conserved and γPLI-Bs diversified. Mathematical analysis of the nucleotide sequences of Protobothrops γPLI-B cDNAs revealed that the particular loops in the three-finger motifs diversified by accelerated evolution. Such evolutionary features should have made serum PLIs acquire their respective inhibitory activities to adapt to venom PLA₂ isozymes.     

A [Lys49]phospholipase A2 from Protobothrops flavoviridis Venom Induces Caspase-Independent Apoptotic Cell Death Accompanied by Rapid Plasma-Membrane Rupture in Human Leukemia Cells

Protobothrops flavoviridis venom contains plural phospholipase A₂ (PLA₂) isozymes. A [Lys⁴⁹]PLA₂ called BPII induced cell death in human leukemia cells. PLA2, an [Asp⁴⁹]PLA₂ that has much stronger lipolytic activity than BPII, failed to induce cell death. BPII-treated cells showed morphological changes, DNA fragmentation, and nuclear condensation. This BPII-induced apoptotic cell death was neither inhibited by inhibitors of caspases 3 and 6 nor accompanied by activation of procaspase 3, indicating that BPII-induced cell death is caspase independent. Since inactive p-bromophenacylated BPII induced cell death, BPII-induced apoptotic cell death is independent of PLA₂ lipolytic activity. Rapid externalization of phosphatidylserine in BPII-treated cells was observed for fluorescein isothiocyanate (FITC)-labeled annexin V. In the cells treated with BPII, this spread over the cell membranes, implying that the cell toxicity of BPII is mediated via its cell-surface receptor.     

A New Species of the Genus Protobothrops(Squamata: Viperidae) from Southern Tibet,China and Sikkim,India

A new species of the genus Protobothrops Hoge Romano-Hoge, 1983, was described from Jilong County, southern Tibet, China, and Chungthang, northern Sikkim, India. It differs from congeners by the following characters: 1) relatively large body size(total length up to 1510 mm); 2) dorsal scale rows 25–25–19; 3) except for the smooth outermost row, dorsal scales are weakly keeled; 4) relatively high number of ventral(198–216) and subcaudal(65–76 pairs) scales; 5) 7–8 supralabials; 6) 11 to 13 infralabials; 7) dorsal head uniform dark brown, laterally a reddish-brown obscure postocular streak; 8) dorsum of trunk and tail olive, with distinct black edged red brown transverse bands across the body and tail; and 9) eye from bright brown and reddish brown to mildly brown. The new species was also observed from the Haa Valley in western Bhutan.     

广东天井山林区发现角原矛头蝮

2009年4～7月,在广东天井山林区采集到3条角原矛头蝮(Protobothrops cornutus),这是该蛇在我国野外第二次被发现,天井山是新发现的一个分布点。本次野外新发现进一步证实了角原矛头蝮在我国的自然分布,为深入了解该蛇的形态特征及地理分布格局提供了重要基础资料。     

N49 phospholipase A2, a unique subgroup of snake venom group II phospholipase A2

A novel phospholipase A₂ (PLA₂) with Asn at its site 49 was purified from the snake venom of Protobothrops mucrosquamatus by using SP-Sephadex C25, Superdex 75, Heparin-Sepharose (FF) and HPLC reverse-phage C₁₈ chromatography and designated as TM-N49. It showed a molecular mass of 13.875 kDa on MALDI-TOF. TM-N49 does not possess enzymatic, hemolytic and hemorrhagic activities. It fails to induce platelet aggregation by itself, and does not inhibit the platelet aggregation induced by ADP. However, it exhibits potent myotoxic activity causing inflammatory cell infiltration, severe myoedema, myonecrosis and myolysis in the gastrocnemius muscles of BALB/c mice. Phylogenetic analysis found that that TM-N49 combined with two phospholipase A₂s from Trimeresurus stejnegeri, TsR6 and CTs-R6 cluster into one group. Structural and functional analysis indicated that these phospholipase A₂s are distinct from the other subgroups (D49 PLA₂, S49 PLA₂ and K49 PLA₂) and represent a unique subgroup of snake venom group II PLA₂, named N49 PLA₂ subgroup.     

烙铁头蛇咬伤后迟发性出血的临床分析

目的探讨烙铁头蛇咬伤后迟发性出血的临床特点及治疗方法。方法对我院11例烙铁头蛇咬伤后出现迟发性出血的患者进行回顾性分析,总结其临床特点及治疗方法,并分析其病因。结果迟发性出血通常发生在烙铁头蛇咬伤后的第5～6天,发病率约16.42%;11例患者均出现伤口流血不止、皮下淤斑、牙龈出血及鼻衄,其中1例伴有便血及血尿,同时凝血酶原时间、活化部分凝血活酶时间及凝血酶时间均显著延长。经及时给予抗蛇毒血清、补充血容量等治疗,11例患者均痊愈。结论烙铁头蛇咬伤后迟发性出血并不少见,及早发现、积极处理是治愈的保证。     

莽山烙铁头蛇毒液蛋白质组学研究(英文)

目的收集一条中国特有品种莽山烙铁头蛇的新鲜毒液,对其蛇毒蛋白作生化分析。方法先以电泳胶片法分析比较莽山烙铁头蛇毒与中国大陆及台湾、日本琉球各地其它品种的烙铁头蛇和各地其他品种的烙铁头蛇的粗蛇毒,在凝胶电泳中展现之异同。然后利用高效液相色谱法(HPLC)将莽山烙铁头蛇毒中的磷脂酶分离,再以质谱仪等鉴定,并与以往相同方法分析莽山烙铁头蛇所得到的磷脂酶分析结果比较。结果我们的研究证实了莽山烙铁头蛇毒含唯一主要的磷脂酶,其含量大约占蛇毒总重量的58%,与中国其他烙铁头蛇品种及日本琉球烙铁头蛇的蛇毒某些碱性磷脂酶之氨基酸序列及蛋白结构特别相似。此碱性磷脂酶主要毒性是水肿、局部炎症及肌肉坏死。结论莽山烙铁头蛇咬伤的临床表现为抗凝与出血,局部炎症坏死等特点,亦可由其蛇毒成分得到印证与解释。     

Effect of Ageing on the Oxidative Browning of Sugar-Amino Acid Model Systems

Sugar-amino acid model systems were aged for 3 months under anaerobic or aerobic conditions. Subsequently, these aged model systems were stored for 2 weeks at 37°C under aerobic conditions to examine “oxidative browning.” The results obtained were as follows:

1. The oxidative browning of the model systems increased with increase of the ageing period. Fe²⁺ increased the effects of the ageing.

2. The model systems aged under anaerobic conditions darkened more than those aged under aerobic conditions during storage for 2 weeks.

3. An Amadori rearrangement product, 1-deoxy-1-glycino-d-fructcse was isolated from the aged glucose-glycine model system and it caused a marked increase in the rate of the oxidative browning. Therefore, Amadori rearrangement products are considered to be important precursors in the oxidative browning reaction.

     

蛇伤凉血合剂治疗烙铁头蛇咬伤临床观察

目的观察蛇伤凉血合剂对烙铁头蛇咬伤的临床疗效。方法将68例病人分为两组,均给予常规治疗。治疗组加服蛇伤凉血合剂。观察比较两组疗效及肿胀消退时间、疼痛缓解时间、局部坏死发生率、肢体功能受限发生率、住院时间等指标。蛄果两组病人临床疗效、肿胀消退时间、疼痛缓解时间、局部坏死发生率、肢体功能受限发生率、住院时间均有显著性差异（P〈0．05）．蛄论蛇伤凉血合剂对烙铁头蛇咬伤有显著疗效。     

A novel recombinant system for functional expression of myonecrotic snake phospholipase A(2) in Escherichia coli using a new fusion affinity tag

A novel recombinant expression system in Escherichia coli was developed using conger eel galectin, namely, congerin II, as an affinity tag. This system was applied for the functional expression of myotoxic lysine-49-phospholipase A₂ ([Lys⁴⁹]PLA₂), termed BPII and obtained from Protobothrops flavoviridis (Pf) venom. Recombinant Pf BPII fused with a congerin tag has been successfully expressed as a soluble fraction and showed better quantitative yield when folded correctly. The solubility of the recombinant congerin II-tagged BPII increased up to >90% in E. coli strain JM109 when coexpressed with the molecular chaperones GroEL, GroES, and trigger factor (Tf). The tag protein was cleaved by digestion with restriction protease, such as α-thrombin or Microbacterium liquefaciens protease (MLP), to obtain completely active recombinant BPII. Thus, the congerin-tagged fusion systems containing the cleavage recognition site for α-thrombin or MLP were demonstrated to be highly efficient and useful for producing proteins of desired solubility and activity.