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毒液和有毒動物一直使人類著迷，在人類歷史上，它們很早就開始被用作藥物。60多年來，DSM Pentapharm公司一直參與蛇毒的研究。該公司已多次將源自蛇毒的新型活性化合物成功帶入市場，應用于制藥和診斷。

蛇毒的常見作用機制是干擾人體止血系統(tǒng)。對凝血或纖維蛋白溶解相關的幾乎所有蛋白，都存在一種毒素蛋白可以模擬、激活或滅活它。影響止血的蛇毒毒素根據其整體效應分為以下幾組：

凝血因子:類凝血酶、凝血酶原激活劑和凝血V因子和凝血X因子激活劑

抗凝血因子:包括凝血IX因子 / 凝血X因子結合蛋白、蛋白C激活劑、凝血酶抑制劑和磷脂酶A2

作為血小板活化劑或抑制劑的蛋白質: 包括金屬蛋白酶在內的蛋白酶、C型凝集素、解聯蛋白、磷脂酶A2和L-氨基酸氧化酶

影響纖維蛋白溶解的因子:纖溶酶和纖溶酶原激活劑

出血毒素: 金屬蛋白酶降解血管細胞外基質

這些毒液成分中很多對凝血因子都具有特異性，同時它們對止血系統(tǒng)中的很多抑制劑也不敏感。所以，它們對于特定的凝血障礙的診斷分析較少受到干擾因素的影響，從而可以提供可便利的診斷方法：

1）使用蛇毒類凝血酶（SVTLE）如巴曲酶和Pefakit?立止血?時間，可以測量含有肝素或者直接口服抗凝劑的樣品中的抗凝血酶III、纖維蛋白原和纖維蛋白原分解產物，以及檢測纖維蛋白原功能障礙。

2）可以根據相關的輔因子依賴性，使用不同的蛇毒凝血酶原激活劑（例如ecarin和noscarin）進行凝血酶原、凝血酶原功能異常、以及中間凝血酶和非酶形式的凝血酶的測定。

3）可以通過蝰蛇蛇毒中的RVV-V和RVV-X酶來測定凝血因子V、VII和X以及重要的狼瘡抗凝物（LA）。

4）可以使用蛇毒激活劑來進行狼瘡抗凝物的篩選，包括RVV-X和凝血酶原激活劑，如textarin和ecarin。

5）可以通過Protac?和Pefakit? APC-R試劑盒測量蛋白C、蛋白C系統(tǒng),以及活化的蛋白C抗性（APCR,其在歐美被認為是導致血栓的形成主要原因）。Pefakit? APC-R試劑盒中使用了 RVV-V和noscarin。

6）可以通過含有RVV-V的Pefakit?PiCT?試劑盒來診斷抗凝劑，如間接凝血酶抑制劑（普通肝素UFH、低分子量肝素LMWH）或直接FXa抑制劑和直接凝血酶抑制劑（DTIs）。

7）血小板：血管性血友病因子（vWF）和相關綜合征（伯納 - 蘇里爾病和IIa型血友�。┛赏ㄟ^Botrocetin?進行研究

除上述內容及在凝血實驗中常用測定之外，還可使用蛇毒蛋白質（如解聯蛋白、金屬蛋白酶和C型凝集素）來研究血小板糖蛋白受體、血小板 - 血小板和血小板 - 內皮相互作用性質。例如，Convulxin（一種從Crotalus durissus terrificus毒液中分離的異二聚體C型凝集素）在生理條件下通過結合和聚集GPVI-受體以激活哺乳動物血小板。GPVI的占據和聚集激活Src家族激酶，磷酸化Fc受體γ鏈并激活對血小板下游活化至關重要的p72SYK。

蛇毒與其所富含的蛋白是豐富的活性化合物來源，其中許多活性化合物已被應用于凝血領域。這些化合物被廣泛使用于凝血實驗中，用于凝血和纖維蛋白溶解過程中各種參數的常規(guī)測定，并促進了對其基本生物學機制的理解。當前進行的研究主要關注新蛇毒組分的分離和表征，為未來止血診斷和治療領域提供新工具。

DSM Pentapharm是一家總部位于瑞士的專注于凝血診斷原料及試劑的公司。DSM Pentapharm積極拓展中國區(qū)業(yè)務,現尋求有實力、致力于凝血診斷領域發(fā)展的經銷商伙伴合作，有意者請聯系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.