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Little is known about the detailed clinical description, pathophysiology, and efficacy of treatments for ocular envenoming (venom ophthalmia) caused by venom of the spitting elapid and other snakes, as well as ocular complications caused by snake venom injection. In this paper, we review clinical information of case reports regarding venom ophthalmia and snake venom injection with associated ocular injuries in Asia, Africa, and the United States. We also review the literature of snake venom such as their compositions, properties, and toxic effects. Based on the available clinical information and animal studies, we further discuss possible mechanisms of venom ophthalmia derived from two different routes (Duvernoy’s gland in the mouth and nuchal gland in the dorsal neck) and the pathophysiology of snake venom injection induced ocular complications, including corneal edema, corneal erosion, cataract, ocular inflammation, retinal hemorrhage, acute angle closure glaucoma, as well as ptosis, diplopia, and photophobia. Finally, we discuss the appropriate first aid and novel strategies for treating venom ophthalmia and snake envenoming.

The Imperial Japanese Army possessed different types of chemical weapons and used them frequently in China during World War II (WWII). At the end of WWII, Japan abandoned all the chemical weapons by dumping them into the sea and burying them underground. It has been 65 years since the end of WWII. During this time, many of the containers holding the weapons have rotted and the chemical agents leaked out causing multiple casualties especially in China. In this review, the brief history of Japanese chemical weapons is discussed along with the variety of chemical weapons the Japanese Army possessed during WWII. Finally, the destruction caused by the leftover chemical weapons, especially in China, is described.

Sea snakes (family: Hydrophiidae) are serpents found in the coastal areas of the Indian and Pacific Oceans. There are two subfamilies in Hydrophiidae: Hydrophiinae and Laticaudinae. A toxin, aagardi toxin, was isolated from the venom of the Hydrophiinae snake, Hydrophis torquatus aagardi and its chemical properties such as molecular weight, isoelectric point, importance of disulfide bonds, lack of enzymatic activity and amino acid sequence were determined. The amino acid sequence indicated a close relationship to the primary structure of other Hydrophiinae toxins and a significant difference from Laticaudinae toxins, confirming that primary toxin structure is closely related to sea snake phylogenecity.

Melamine is a raw ingredient for the manufacture of plastics, but it is frequently misused by adding it to food to raise the nitrogen content, thereby giving the false impression of a high protein content. Varied amounts of melamine were added to samples of dried milk obtained from five manufacturers in Japan. The samples were illuminated by a small cross section of a laser beam and the scattered light was examined. The presence of melamine in milk could be immediately detected without any chemical or physical alteration of the milk by interpreting its Raman scattering spectra. Among the many Raman bands, an intense band at 676 cm−1 was the most useful for detecting melamine; the detection limit was about 1% (w/w). Because this method does not extract melamine from the dried milk sample, it reduces the risk of error that may occur during extraction or from interaction with chemical reagents. The method provides a very rapid screening test for melamineadulterated dried milk in food chemistry and forensic toxicology.

The complete primary structure of a lethal toxin, horridum toxin, from the venom of the lizard, Heloderma horridum horridum, was determined by Edman degradation. The amino acid sequence was deduced by overlapping peptide fragments generated by chemical and enzymatic digestions. Horridum toxin causes hemorrhage in internal organs and particularly in the eye, leading to exophthalmia, an effect that has not been observed for other toxins. It is a glycoprotein with a total of 210 residues. Examination of the primary sequence revealed that horridum toxin has considerable homology to tissue-type kallikrein and trypsin. Furthermore, synthetic substrates for trypsin, such as tosyl-L-arginine methyl ester, benzoyl-L-arginine ethyl ester and other p-nitroanilide substrates, were hydrolyzed. The toxin released bradykinin upon hydrolysis of kininogen. This enzymatic behavior is similar to that of plasma kallikrein: however, the presence of a characteristic "kallikrein-like" loop at 91-100 (GTIYNCNYVN) in the primary structure and other features similar to tissue kallikrein suggest that horridum toxin is more like tissue kallikrein. This toxin degraded all three chains of fibrinogen but did not form a clot, which suggests that it is different from thrombin. Moreover, it differs from another lethal factor from H. horridum horridum, gila toxin, which has 245 amino acid residues and does not cause exophthalmia.

Nerve gas is a chemical weapon and was previously thought to be used solely on the battlefield. This assumption was shattered when Aum Shinrikyo, a new Buddhist sect, sprayed sarin onto a totally innocent civilian population on the night of June 27, 1994, in the quiet town of Matsumoto City in Japan. The sarin terrorist attack in Matsumoto City was a prelude to another attack on an even larger scale that shocked the entire world: the Tokyo subway terrorism with sarin by the same sect, 8 months after the Matsumoto incident on March 20, 1995. For a few months after the Matsumoto City case, no one knew who sprayed the sarin or for what purpose. Even after the Tokyo subway sarin attack and the arrest of many cult members, the detailed information as to how the sarin was detected and made were unknown to the public for many years. Part of the reason was the secretive nature of the Japanese police authority. However, after the passage of 10 or more years detailed information about Aum Shinrikyo's chemical terro...

Snake venom research before 1945 in Taiwan is summarized. The year of 1945 had significant meaning in the history of Taiwan because this was the year Japanese colonial rule ceased. From this year on, Taiwanese scientists started their own work. During the colonial days, the Japanese developed Taiwan into a modern society, making a foundation for future industrial development in Taiwan. Taiwan has been recognized as the world leader in snake venom research. Alpha and beta bungarotoxins were discovered by Dr. C. Y. Lee in Taiwan. Taiwan had very strong snake venom research before 1945 because of Professor Tsungming Tu's extensive research. Therefore, it is worthwhile to review the origin of snake venom research in Taiwan before 1945.Taiwan has been recognized as the world leader in snake venom research. Among many venom scientists in Taiwan, Dr. C. Y. Lee was one of the most outstanding scientists.Snake venom research in Taiwan started in the early part of the 1930s. The active venom research could be trace...

Ticks and mites are bloodsucking ectoparasites containing anticoagulants as well as many other bioactive compounds. Because of their extremely small size, collection of venom (saliva) is very difficult. Therefore, the scientific study of tick and mite venoms is far less well developed than that of other venoms such as snake, scorpion, and bee. In this review article, anticoagulant components, paralytic toxins, and the effect of venom on the immune system are reviewed. Anticoagulants are discussed in three parts, namely inhibition of thrombin, inhibition of factor X activation, and effect on other blood coagulation factors. Among the venom (saliva) components, lipids, enzymes, and other bioactive components are discussed. Paralysis is discussed without further subdivision. Immunological considerations are reviewed in two ways: their effect on host immune system, and efforts to develop vaccines and toxoids. All together 142 references were quoted.

Geographic venom samples of Crotalus viridis viridis were obtained from South Dakota, Wyoming, Colorado, Oklahoma, Texas, New Mexico, and Arizona. From these samples, the phospholipases A(2) (PLA(2)s) were purified and their N-terminal sequences, precise masses, and in vitro enzymatic activities were determined. We purified two to four distinct acidic PLA(2)s from each sample; some of them displayed different inhibition specificities toward mammalian platelets. One of the acidic PLA(2)s induced edema, but had no anti-platelet activity. There was also a common basic PLA(2) myotoxin in all the samples. We have cloned five acidic PLA(2)s and several hybrid-like nonexpressing PLA(2)s. Molecular masses and N-terminal sequences of the purified PLA(2)s were matched with those deduced from the cDNA sequences, and the complete amino acid sequences of five novel acidic PLA(2)s were thus solved. They share 78% or greater sequence identity, and a cladogram based on the sequences of many venom acidic PLA(2)s of New World pit vipers revealed at least two subtypes. The results contribute to a better understanding of the ecogenetic adaptation of rattlesnakes and the structure-activity relationships and evolution of the acidic PLA(2)s in pit viper venom.

The focus of my research was snake venom research and application of Raman spectroscopy for the biological compounds. In snake venom research, the emphasis was on hemorrhagic toxins, myonecrotic toxins from rattlesnake venoms, and postsynaptic neurotoxins from sea snake venoms. Structure–function relationship of these toxins was pursued using different methods such as biochemical, immunological, electronmicroscopy, biophysical, physiological, and pathological techniques. Many pure components were isolated and their amino acid sequences and biochemical properties were studied. Since a Raman spectrometer was purchased in 1976, it was possible to examine many biological compounds by Raman spectroscopy. Peptide backbone conformation and some side chain microenvironment of many proteins, kidney stones, and gallstones, etc. were examined by Raman scattering method. Raman spectroscopy can identify many biological compounds directly by focusing laser light without using wet chemical analysis. I was extremely fort...

Basic phospholipase A2 homologs with Lys49 substitution at the essential Ca2+-binding site are present in the venom of pit vipers under many genera. However, they have not been found in rattlesnake venoms before. We have now screened for this protein in the venom of rattlesnakes and other less studied pit vipers. By gel filtration chromatography and RP-HPLC, Lys49-phospholipase-like proteins were purified from the venoms of two rattlers, Crotalus atrox and Crotalus m. molossus, and five nonrattlers, Porthidium nummifer, Porthidium godmani, Bothriechis schlegelii, Trimeresurus puniceus, and Trimeresurus albolabris. Their N-terminal amino acid sequences were shown to be characteristic for this phospholipase subfamily. The purified basic proteins from rattlesnakes caused myonecrosis and edema in experimental animals. We have also cloned the cDNAs and solved the complete sequences of four novel Lys49-phospholipases from the venom glands of C. atrox, P. godmani, B. schlegelii, and Deinagkistrodon acutus (hundred-pace). Phylogenetic analyses based on the amino acid sequences of 28 Lys49-phospholipases separate the pitviper of the New World from those of the Old World, and the arboreal Asiatic species from the terrestrial Asiatic species. The implications of the phylogeny tree to the systematics of pit vipers, and structure–function relationship of the Lys49-phospholipases are discussed.

Myotoxin a , isolated from C. viridis viridis venom, is a myonecrotizing agent present in many snake venoms. A cDNA library was prepared from mRNA obtained from the venom glands of a C. viridis viridis. The complete base sequence of a cDNA corresponding to an mRNA encoding myotoxin a was determined. The 5′ untranslated region has 15 nucleotides, while the 3′ untranslated region has 109 nucleotides. The translated portion of the myotoxin a cDNA encodes a start methionine, a signal peptide, the myotoxin a peptide sequence, and an additional lysine residue. It is likely that myotoxin a is secreted as the cDNA encodes a signal peptide immediately 5′ to the myotoxin a peptide code.

化学兵器は第一次世界大戦中に誕生し盛んに使われたが,その後大規模にはあまり使われなかった。しかし最近その有用性が再認識され,この古い兵器が再び脚光を浴びるようになった。化学兵器は原料もたやすく手に入り,製造も簡単なため,貧乏国の核爆弾といわれる。オウム真理教のサリンテロ行為で,化学兵器は戦場のみならず,これからは公衆に対してテロリズムに使われる可能性がますます強くなった。本文は化学兵器の生体に対する毒作用と治療が目的であるが,限られた誌面ですべての化学兵器について述べることは不可能なので,神経ガスに重点を置き,他のガスの作用は比較的簡略に述べた。多くの種類の化学兵器があるが,実際に兵器として採用されている数は比較的少ない。アメリカ軍を例にとっても実際に化学兵器として採用され,貯蔵されているのはサリン,タブン,VX,マスタードガス,ルイサイトの5種類のみである。神経ガスは神経伝達に必要なアセチルコリンエステラーゼの作用を阻害する。それに対する薬はいろいろあるが,どの薬もすべての神経ガスに一様に効くわけではない。薬の効果は神経ガスによって異なる。オキシム系の薬(例えばPAM)とアトロピンとの併用は,単独で使うより治療効果が大とみなされている。ジアゼパムは痙攣を防ぐのに効果があり,三者併用はさらによいといわれている。他の毒ガス,例えばマスタードガス,ホスゲン等には特効薬はなく,対症治療が主な方法である。既存の毒ガスのみならず,新しい型の毒ガスにも注意し,その治療法についても検討すべきである。

The complete amino acid sequence of lebetase is deduced from the nucleotide sequence of a cDNA clone isolated by screening a venomous gland c DNA library of Central Asian Vipera lebetina snake. The cDNA sequence with 2011 basepairs encodes an open reading frame of 478 amino acids which includes an 18 amino acid signal peptide, plus an 175 amino acid segment of zymogen-like propeptide, a mature protein of 204 amino acids, a spacer of 18 amino acids and a disintegrin-like peptide of 63 amino acids. The mature protein lebetase as isolated from the crude venom has the molecular weight of approximately 23.7 kD and, thus, lebetase as well as several other snake venom metalloproteinases is translated as a precursor protein, which may be processed posttranslationally. The lebetase proprotein has a “cysteine switch” motif (PKMCGV) similar to that involved in the activation of matrix metalloproteinase zymogens. The mature protein (residues 223-427) shows the strongest similarity with fibrolase(63% identity), fibrinolytic enzyme from Agkistrodon contortrix contortrix venom. The metalloproteinase domain has a typical zinc-chelating sequence (HEXXHXXGXXH). In the disintegrin-like domain of protein, the RGD sequence is replaced by VGD.

Antibodies to two fractions of fibrinolytic enzyme in Vipera lebetina venom were produced by immunizing mice with chromatographically purified lebetase probes. The antibodies were isolated from mice blood by protein A affinity chromatography. The antibodies to both fractions reacted only with the fibrinolytic enzyme in V. lebetina venom as demonstrated by western immunoblotting. Immunodot assays, ELISA and western immunoblotting revealed that 11 snake venoms including species of Viperidae and Crotalidae but not Elapidae cross-react with lebetase antibodies to varying degrees. The molecular weights of cross-reacting components were detected and compared with the earlier published data.

A variety of snake venoms was tested for the ability to inhibit the binding of antagonists to specific muscarinic acetylcholine receptors (mAChRs); the highest activity was found in the venom of Naja naja sputatrix. The active principle in this venom was isolated by column chromatography on Sephadex G-50, Sephadex G-150, and CM-Sephadex C-25. The final preparation was homogeneous as determined by polyacrylamide gel electrophoresis and HPLC; about sevenfold purification was achieved with a yield of 12%. The isolated active component, which was designated "muscarinic inhibitor," was found to displace various antagonists from rat synaptosomal membranes, which contain all subtypes of mAChRs. The m1 and m2 recombinant human receptors were also competitive with N. naja sputatrix muscarinic inhibitor. This antagonist-displacing action was dose dependent, but was independent of the reaction temperature. The isolated muscarinic inhibitor was determined to be a 13.6 kDa, monomeric, neutral protein and to have an N-terminal amino acid sequence which is highly homologous with phospholipase A2 from the venoms of genus Naja. N. naja sputatrix muscarinic inhibitor could hydrolyze phosphatidylcholine in a dose- and temperature-dependent manner. This phospholipase A2 enzymatic activity was augmented by the addition of the calcium ion, while it was almost completely abolished by a competitive inhibitor of phospholipase A2 enzymes. However, the antagonist-displacing activity was only slightly affected by these agents. The treatment of the muscarinic inhibitor with p-bromophenacyl bromide, which selectively modifies the histidine residue in the catalytic site of a phospholipase A2 enzyme, caused completed elimination of both activities. These findings indicate that N. naja sputatrix muscarinic inhibitor is a protein with two distinct activities, phospholipase and antagonist displacement, the active centers of which may be in close physical proximity for both actions. This is the first finding that a phospholipase A2 is an inhibitor of the muscarinic receptor.

Nerve gas is a major chemical agent stockpiled as a chemical arsenal. Nerve gas was used in actual combat in the Iran-Iraq war and also in the insurgent war against Kurd minorities in Iraq. Recently, a nerve gas, sarin, was used massively against a defenseless public in Matsumoto and in Tokyo, causing a large number of deaths and injuries. This marked the first use of chemical weapons in a noncombat situation by a terrorist group. Information on nerve gas is relatively scarce; it is not easily accessible to most people. A systematic summarized article like the one here should help those who are interested in an overview of scientific information on nerve gas.In this review article, an overall view of poisonous gas is first made. Then different aspects of nerve gas are discussed. Toxicology, treatment, detection, decontamination and control of precursors are also reviewed.

Snake venoms, especially from the Crotalidae family, contain a variety of enzymes that prevent blood coagulation by virtue of their fibrinolytic enzymes. Nineteen snake venoms were screened for fibrinolytic activity and the highest activity was found in the venom of Crotalus basiliscus basiliscus venom. The active principle, basilase, was isolated, purified, and found to have fibrinolytic and fibrinogenolytic activity. It had a molecular weight of 22,000 and 1 mol of zinc per mole of protein associated with it. The proteolytic activity of the enzyme against dimethyl casein was inhibited by ethylenediaminetetraacetic acid and alpha 2-macroglobulin. It did not inactivate alpha 2-macroglobulin. Basilase did not have any of the following activities: thrombin-like, factor X-like, protein C activating, or urokinase-like. It caused neither hemorrhage nor platelet aggregation. In spite of its proteolytic activity, basilase did not hydrolyze the membranes of platelets. Basilase had 24% alpha-helix, 31% beta-sheet, 25% turns, and 20% unordered structure, as determined by Fourier Transform Infrared spectroscopy. Basilase is an enzyme that hydrolyzes fibrin directly without activation of plasminogen.

Atroxase, isolated from the venom of Crotalus atrox (western diamondback rattlesnake), is a nonhemorrhagic protease which has fibrinolytic activity in vivo . The primary structure of atroxase was deduced from the cDNA encoding the atroxase protein. The venom glands of Crotalus atrox were used to prepare a cDNA library. Degenerate oligonucleotides mere synthesized based on the partial amino acid sequence of atroxase and were used as primers in the polymerase chain reaction to amplify overlapping cDNA fragments from the C. atrox cDNA library. The resulting cDNA fragments were subcloned, sequenced, and translated. The final nucleotide sequence shows high homology to previously described primary structures of nonhemorrhagic fibrinolytic proteases isolated from snake venom.

The activity and the complete primary structure of gilatoxin, a glycoprotein component from the venom of the Mexican beaded lizard (Heloderma horridum horridum) has been elucidated. Gilatoxin, a serine protease, showed kallikrein-like activity, releasing bradykinin from kininogen; toxin-treated kininogen also produced lowered blood pressure in rats and contraction of isolated rat uterus smooth muscle. Gilatoxin catalyzed the hydrolysis of various arginine ester substrates for trypsin and thrombin and degraded both angiotensin I and II by cleavage of the dipeptide Asp-Arg from the NH2-terminal end. Fibrinogen was degraded but a fibrin clot was not produced, indicating that gilatoxin has specificities different from thrombin and snake venom thrombin-like proteases. The complete amino acid sequence of gilatoxin (245 residues) was deduced from NH2-terminal sequencing of overlapping peptide fragments cleaved from the reduced and alkylated toxin by enzymatic and chemical methods. The toxin is extensively glycosylated, containing approximately 8 mol of monosaccharide/mol of toxin, but appears to lack O-glycosylation sites. Amino acid sequence alignment of gilatoxin with batroxobin, crotalase, kallikrein, thrombin, trypsin, and several partial sequences of other Heloderma toxins reveals that there is considerable homology between these enzymes, particularly in the regions of the presumed catalytic site. Gilatoxin contains an additional 7 residues in the highly conserved catalytic region of serine proteases (including Asp-96, in the basic specificity pocket of thrombin) which may contribute to the unusual substrate specificity of the toxin.

Raman spectroscopic analysis of kidney stones of mixed composition and of unusual stones is presented. Raman spectroscopy was used to analyze the chemical composition of kidney stones without extraction. A kidney stone sample was irradiated by laser light of 514.5 nm, and the scattered light was analyzed by a Raman spectrometer. The first stone was determined to be a mixture of calcium oxalate dihydrate and hydroxyapatite and the second one to be a mixture of calcium oxalate monohydrate, uric acid, and hydroxyapatite. The third and fourth stones were not mixed-composition stones, but rather stones with unusual composition. One was concluded to be carboxyapatite, and the other was mucoprotein-type stone. The present investigation indicates that Raman spectroscopy is a useful tool for direct analysis of kidney stone without going through the usual procedure of crushing, extracting, and carrying out tedious wet chemical analysis.

Colubridae is a family of snakes that comprise more than fifty percent of all living snakes. As their fangs are located in the rear of the mouth, they are generally considered non poisonous. In the first part of this review, cases of envenomation by about fifteen kinds of colubridae are described. Notable clinical symptoms are edema, pain, blood coagulation and in some cases respiratory arrest. Relatively few studies have been carried out on these snakes as compared to other families such as Crotalidae, Elapidae and Viperidae. The toxicity of these snakes ranges from 0.071–33.00 mg/kg, indicating that some are extremely toxic while the others are not. The venoms from these snakes have been shown to contain proteolytic enzymes. Phospholipase A2, phosphodiesterase and L-amino acid oxidase are some of the other enzymes present. The presence of a very interesting neurotoxic component has also been observed. Much more biochemical studies on this will be able to shed some light on evolutionary links bet...

Both sea snakes and cobras have venoms containing postsynaptic neurotoxins. Comparison of the primary structures indicates many similarities, especially the positions of the four disulfide bonds. However, detailed examination reveals differences in several amino acid residues. Amino acid sequences of sea snake neurotoxins were determined, and then compared to cobra neurotoxins by computer modeling. This allowed for easy comparison of the similarities and differences between the two types of postsynaptic neurotoxins. Comparison of computer models for the toxins of sea snakes and cobra will reveal the three dimensional difference of the toxins much clearer than the amino acid sequence alone.

The synthetic approach to the structure-function relationship of lapemis toxin has been very useful in clarifying the important binding regions. To identify the neurotoxic binding domain(s) of lapemis toxin, several peptides were synthesized using the 9-fluorenylmethoxycarbonyl protocols. These peptides were based on the sequence of lapemis toxin, a 60-amino-acid, shortchain postsynaptic neurotoxin found in sea snake ( Lapemis hardwickii ) venom. The peptides were purified using high-performance liquid chromatography and sequenced to verify the correct synthesis, isolation, and purity. The synthetic peptide names and single letter sequences were Peptide A1 (15 mer) CCNQQSSQPKTTTNC Peptide B1 (18 mer) CYKKTWSDHRGTRIERGC Peptide B2 (16 mer) YKKTWSDHRGTRIERG Peptide C1 (12 mer) CPQVKPGIKLEC Peptide NS (20 mer) EACDFGHIKLMNPQRSTVWY. The peptide NS (nonsense peptide) sequence was arbitrarily determined and used as a control peptide. Biological activities of the synthetic peptides were determined by in vivo as well as by in vitro assay methods. For the in vivo assay, lethality was determined by intravenous injection in mice (Swiss Webster). For the in vitro assay, peptide binding to the Torpedo californica nicotinic acetylcholine receptor was determined. The peptides were found to be nontoxic at approximately 114 times the known LD 50 of lapemis toxin. Binding studies with 125 -Iradiolabeled lapemis toxin and tyrosine-containing peptides indicated that lapemis toxin and peptide Bl bound the receptor, while the other peptides had no detectable binding. The central loop domain of lapemis toxin (peptide B1) plays a dominate role in the toxin's binding ability to the receptor. These results and the hydrophilicity analysis predict peptide B1 may serve as an antagonist or antigen to neutralize the neurotoxin effects in vivo .

The interaction of myotoxin alpha with intact sarcoplasmic reticulum (SR) components was investigated, and two SR proteins were identified that associated with myotoxin a. One of the proteins has an apparent molecular weight similar to the Ca(2+)-ATPase, the major SR protein responsible for calcium loading. Ca(2+)-ATPase was purified, and its interaction with myotoxin a was studied. Evidence for specific binding of myotoxin a to Ca(2+)-ATPase was established by isolating chemically cross-linked myotoxin a-Ca(2+)-ATPase complexes and further proving their association with anti-myotoxin a antibodies. The binding region of myotoxin a was further delineated by cleaving the protein with cyanogen bromide (CNBr) into two fragments, a larger N-terminal fragment of 28 residues and a smaller C-terminal fragment of 14 residues. Competition experiments with 125I-myotoxin a showed that the C-terminal fragment competed better against 125I-myotoxin a than the N-terminal fragment for SR protein binding. Two overlapping peptides covering the sequence of the N-terminal fragment were synthesized to clarify the interaction of the N-terminal fragment of myotoxin a with SR proteins. A 16-residue peptide corresponding to residues 1-16 competed strongly with 125I-myotoxin a, while a second peptide (residues 13-28) did not.

Cerastobin, a thrombinlike enzyme with arginine esterase activity, was purified from crude Cerastes vipera (Egyptian Sahara snake) venom. Unlike thrombinlike enzymes isolated from other snake venoms, cerastobin had a potent platelet aggregatory effect. The activation of human platelets was not related to adenosine diphosphate release and/or prostaglandin synthesis. Cerastobin showed a proteolytic activity towards protein constituents of the platelets’ cytoskeleton. It hydrolyzed actin, actin-binding protein, and P235. This may explain at least a part of the aggregatory mechanism(s) of cerastobin. Electron microscopic studies of the stimulated platelets revealed changes in their morphology, including the appearance of pseudopodia, dilatation of the canalicular system with the formation of peripheral balloons, and centralization of the platelet organelles. Some inhibitors of the esteratic activity of cerastobin also inhibited its ability to aggregate platelets.

Boophilus calcaratus is a tick found in Central Asia and a common parasite to domestic animals. Venom from this tick was fractionated by two-step column chromatography, Sephadex G-75, and DEAE-Sephadex A-25. The homogeneity of the anticoagulant was examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The purified component is named calcaratin and has a molecular weight of 14,500. The effect of the purified anticoagulant component (calcaratin) on various sites of the blood coagulation cascade scheme was examined and compared with crude venom. The chromogenic substrates S-2238 (H-D-Phe-Pip-Arg-pNA 2HCl) for thrombin and S-2765 (N-alpha-Z-D-Arg-Gly-Arg-pNA 2HCl) for factor Xa were also investigated. Activated partial clotting times were all prolonged, suggesting the anticoagulation nature of the purified component and crude venom. Prolongation of fibrinogen clotting time (FCT) is highly suggestive of the antithrombin property of the purified component and its original venom.

Sea snake venoms contain less protein than those of land snakes (Toom et al., 1969). Sea snake venoms lack arginine ester hydrolyzing activity, whereas those of Crotalidae and Viperidae have such activity (Tu et al., 1966). Sea snakes live in salty water, and their venoms may be different from those of land snakes. Because of the difficulty in obtaining sea snake venoms, information about sea snake venoms is quite incomplete. NGF is commonly present in the venoms of land snakes such as Elapidae, Viperidae, and Crotalidae (Cohen and Levi-Montalcini, 1956; Lipps, 2002). It is therefore of interest to investigate the presence or absence of NGF in sea snake venoms. In order to investigate the presence or absence of NGF, five sea snake venoms were selected. Lapemis hardwickii (Hardwick's sea snake) and Acalyptophis peronii venom were obtained from the Gulf of Thailand. Hydrophis cyanocinctus (common sea snake) and Enhydrina schistosa (beaked sea snake) venom were obtained from the Strait of Malacca. Laticauda semifasciata (broad band blue sea snake) venom was also examined and the venom was obtained from Gato Island in the Philippines.

The effects of snake venom on the cholinergic system have been well-studied; however, no similar studies have been performed on the adrenergic system. Adrenomedullary cells secrete catecholamine (CA) on stimulation; thus they are an ideal system to study the effect of snake venoms on CA secretion or inhibition. Snake venoms from different Families and Genera were investigated. All snake venoms investigated, caused CA efflux. CA can be released when cytolysis takes place; so in order to assert CA efflux was not due to cytolysis, venoms were added after the cells were treated with KCl. Most venom, with the exception of sea snake (Hydrophiidae) venom, was found to induce CA release due to cytolysis. The effects of purified components such as phospholipase A2, neurotoxin I, and cardiotoxin were also investigated. Neurotoxin I caused neither cytolysis nor CA efflux. Cardiotoxin caused marked cytolysis, but with slightly less damaging effects than that of cobra venom. Some ion channel blockers prevented cytolysis induced by cardiotoxin. The CA efflux induced by cardiotoxin may be mediated through Ca2+ channels because the efflux could be completely depressed by a Ca2+ channel blocker (1 mM CdCl2).

Myotoxin a is a muscle-degenerating toxin isolated from the venom of Crotalus viridis viridis (prairie rattlesnake). It is composed of 42 amino acid residues with four disulfide bonds. The presence of myotoxin a and related myotoxins is common in various snake venoms. It was found recently that myotoxin a is an uncoupler of calcium ion influx in sarcoplasmic reticulum (SR). Myotoxin a is known to interact with artificial membranes. Since the biological action of myotoxin a affects the calcium pump that is present in the SR membranes, it is of interest to investigate the interaction of SR membrane with myotoxin a by Raman spectroscopy. Raman spectroscopy is particularly useful in membrane study because the C-C and C-H stretching vibrational bands are particularly sensitive in phospholipid phase transition from gel to liquid crystal.

Snake venoms are a rich source of enzymes including many hydrolytic enzymes. Some enzymes such as phospholipase A2, proteolytic enzymes, and phosphodiesterases are well characterized. However many enzymes, such as the glycosidase, hyaluronidase, have not been studied extensively. Here we describe the characterization of snake venom hyaluronidase. In order to determine which venom was the best source for isolation of the enzyme, the hyaluronidase activity of 19 venoms from Elapidae, Viperidae, and Crotalidae snakes was determined. Since Agkistrodon contortrix contortrix venom showed the highest activity, this venom was used for purification of hyaluronidase. Molecular weight was determined by matrix-assisted laser desorption ionization mass spectroscopy and was found to be 59,290 Da. The molecular weight value as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was 61,000 Da. Substrate specificity studies indicated that the snake venom enzyme was specific only for hyaluronan and did not hydrolyze similar polysaccharides of chondroitin, chondroitin sulfate A (chondroitin 4-sulfate), chondroitin sulfate B (dermatan sulfate), chondroitin sulfate C (chondroitin 6-sulfate), chondroitin sulfate D, chondroitin sulfate E, or heparin. The enzyme is an endo-glycosidase without exo-glycosidase activity, as it did not hydrolyze p-nitrophenyl-beta-D-glucuronide or p-nitrophenyl-N-acetyl-beta-D-glucosaminide. The main hydrolysis products from hyaluronan were hexa- and tetrasaccharides with N-acetylglucosamine at the reducing terminal. The cleavage point is at the beta1,4-glycosidic linkage and not at the beta1,3-glycosidic linkage. Thus, snake venom hyaluronidase is an endo-beta-N-acetylhexosaminidase specific for hyaluronan.