毒液和有毒动物一直使人类着迷，在人类历史上，它们很早就开始被用作药物。60多年来，DSM Pentapharm公司一直参与蛇毒的研究。该公司已多次将源自蛇毒的新型活性化合物成功带入市场，应用于制药和诊断。

蛇毒的常见作用机制是干扰人体止血系统。对凝血或纤维蛋白溶解相关的几乎所有蛋白，都存在一种毒素蛋白可以模拟、激活或灭活它。影响止血的蛇毒毒素根据其整体效应分为以下几组：

凝血因子:类凝血酶、凝血酶原激活剂和凝血V因子和凝血X因子激活剂

抗凝血因子:包括凝血IX因子 / 凝血X因子结合蛋白、蛋白C激活剂、凝血酶抑制剂和磷脂酶A2

作为血小板活化剂或抑制剂的蛋白质: 包括金属蛋白酶在内的蛋白酶、C型凝集素、解联蛋白、磷脂酶A2和L-氨基酸氧化酶

影响纤维蛋白溶解的因子:纤溶酶和纤溶酶原激活剂

出血毒素: 金属蛋白酶降解血管细胞外基质

这些毒液成分中很多对凝血因子都具有特异性，同时它们对止血系统中的很多抑制剂也不敏感。所以，它们对于特定的凝血障碍的诊断分析较少受到干扰因素的影响，从而可以提供可便利的诊断方法：

1）使用蛇毒类凝血酶（SVTLE）如巴曲酶和Pefakit?立止血?时间，可以测量含有肝素或者直接口服抗凝剂的样品中的抗凝血酶III、纤维蛋白原和纤维蛋白原分解产物，以及检测纤维蛋白原功能障碍。

2）可以根据相关的辅因子依赖性，使用不同的蛇毒凝血酶原激活剂（例如ecarin和noscarin）进行凝血酶原、凝血酶原功能异常、以及中间凝血酶和非酶形式的凝血酶的测定。

3）可以通过蝰蛇蛇毒中的RVV-V和RVV-X酶来测定凝血因子V、VII和X以及重要的狼疮抗凝物（LA）。

4）可以使用蛇毒激活剂来进行狼疮抗凝物的筛选，包括RVV-X和凝血酶原激活剂，如textarin和ecarin。

5）可以通过Protac?和Pefakit? APC-R试剂盒测量蛋白C、蛋白C系统,以及活化的蛋白C抗性（APCR,其在欧美被认为是导致血栓的形成主要原因）。Pefakit? APC-R试剂盒中使用了 RVV-V和noscarin。

6）可以通过含有RVV-V的Pefakit?PiCT?试剂盒来诊断抗凝剂，如间接凝血酶抑制剂（普通肝素UFH、低分子量肝素LMWH）或直接FXa抑制剂和直接凝血酶抑制剂（DTIs）。

7）血小板：血管性血友病因子（vWF）和相关综合征（伯纳 - 苏里尔病和IIa型血友病）可通过Botrocetin?进行研究

除上述内容及在凝血实验中常用测定之外，还可使用蛇毒蛋白质（如解联蛋白、金属蛋白酶和C型凝集素）来研究血小板糖蛋白受体、血小板 - 血小板和血小板 - 内皮相互作用性质。例如，Convulxin（一种从Crotalus durissus terrificus毒液中分离的异二聚体C型凝集素）在生理条件下通过结合和聚集GPVI-受体以激活哺乳动物血小板。GPVI的占据和聚集激活Src家族激酶，磷酸化Fc受体γ链并激活对血小板下游活化至关重要的p72SYK。

蛇毒与其所富含的蛋白是丰富的活性化合物来源，其中许多活性化合物已被应用于凝血领域。这些化合物被广泛使用于凝血实验中，用于凝血和纤维蛋白溶解过程中各种参数的常规测定，并促进了对其基本生物学机制的理解。当前进行的研究主要关注新蛇毒组分的分离和表征，为未来止血诊断和治疗领域提供新工具。

DSM Pentapharm是一家总部位于瑞士的专注于凝血诊断原料及试剂的公司。DSM Pentapharm积极拓展中国区业务,现寻求有实力、致力于凝血诊断领域发展的经销商伙伴合作，有意者请联系Amy.Chen@dsm.com。

The Use of Snake Venom-Derived Compounds in the Coagulation Laboratory

Venoms and venomous animals have always fascinated man and already very earlyin human history they were used as medicines. For more than 60 years Pentapharm has been involved in the research on snake venoms. At several occasions the company has successfully brought new active compounds derived from snake venom to the market or used these compounds as tools in pharmaceutical and diagnostic applications.

Interference with the functions of the human haemostatic system is a common mechanism of snake venoms. For almost every factor involved in coagulation or fibrinolysis there is avenom protein that can mimic, activate or deactivate it.Snake venom toxins affecting haemostasis have been classified by virtue of theiroverall effect into the following groups:

Coagulant factors(thrombin-like enzymes, prothrombin activators and FV and FX activators)

Anticoagulant factors (including FIX/FX binding proteins, protein C activators,thrombin inhibitors and phospholipases A2)

Proteins acting as activators or inhibitors of blood platelets (proteinases includingmetalloproteinases, C-type lectins, disintegrins, phospholipases A2 and L-amino acid oxidases)

Factors acting on fibrinolysis (fibrinolytic enzymes and plasminogen activator)

Haemorrhagins (metalloproteinases degrading the blood vessel’s extracellularmatrix).

Many of these venom components are acting highly specific on certain coagulation factors. At the same time they often are insensitive to inhibitors of the haemostatic system. Thus, their application for the analysis of particular coagulation disorders is less affected by interfering factors. The set-up of regarding test methods is more convenient in many cases.

1) Antithrombin III, fibrinogen and fibrinogen breakdown products in samples containing heparin or direct oral anticoagulants (DOACs),as well as the detection of fibrinogen dysfunction, can be performed by the use of snake venom thrombin like enzymes (SVTLEs), such as batroxobin and Pefakit? Reptilase? Time.

2) Prothrombin, studies of dysfunctional forms of prothrombin, as well as preparation of meizothrombin and non-enzymatic forms of thrombin, can be performed using different snake venom prothrombin activators in relation to their cofactor dependence (e.g. ecarin and noscarin).

3) Blood clotting factors V, VII and X, and, importantly, lupus anticoagulants (LA)can be assayed by means of enzymes contained in Russell’s viper venom: RVV-V and RVV-X.

4) LA screening, can be performed applying a number of snake venom activators,including RVV-X and prothrombin activators, such as textarin andecarin.

5) Protein C and the protein C pathway, as well as activated protein C resistance,the last being concerned as one of the major causes of thrombophilia, can bemeasured by means of such asProtac? and Pefakit? APC-R using RVV-V and noscarin.

6) Anticoagulants, like indirect (unfractionated heparins (UFH), low molecular weight heparins (LMWH)) or direct FXa inhibitors and direct thrombininhibitors (DTIs) can be monitored by means of Pefakit? PiCT?using RVV-V.

7) Plateles: Von Willebrand factor (vWF) and related syndromes (Bernard-Soulier diseaseand Type IIa von Willebrand disease) can be studied with Botrocetin?

Additionally to the assays mentioned above and commonly performed in thecoagulation laboratory, snake venom proteins, such as disintegrins, metalloproteinases, and C-type lectins are used to study the properties of platelet glycoproteinreceptors, platelet-platelet and platelet-endothelium interactions. For example, Convulxin, a heterodimeric C-type lectin isolated from Crotalusdurissusterrificus venom, activates mammalian platelets via binding and clustering of GPVI-receptors under physiological conditions. Occupation and clustering of GPVI activates Src family kinases, phosphorylating Fc receptor γ-chain and activating p72SYK that is critical for downstream activation of platelets.

Snake venoms with their cocktail of proteins represent a rich source of active compounds many of which have found application as diagnostic tools in the field ofhaemostasis. These are nowadays widely used in the coagulation laboratory andhave facilitated extensively the routine assays of haemostatic parameters and understanding of basic biological mechanisms involved in the clotting and fibrinolysisprocesses. Ongoing research leads to isolationand characterization of new snake venoms components, which are potential tools forfuture applications in the field of haemostasis, in diagnostic as well as therapeuticapproaches.

DSM Pentapharm is now actively developing its market in China and looking for regional distributorship who share the same value and commitments in coagulation diagnosis. For more information, please contactAmy.Chen@dsm.com.