I hope the following might help you (Extracted from a thesis)

Venom Enzymes ;

Biochemists consider snake venoms as one of the most valuable tools in research because of their high enzymatic concentrations(Zaki etal ,1991).

Snake venom contain at lest 26 species types of enzymes, Twelve of these enzymes are common in all venoms ,and the rest occurs separately in certain species. (Lyaniwura ,1991).

Venoms of Viperidae and Crotalidae possess a very strong proteolytic activity, while those of Elapidae and Hydrophiidae have very weak proteolytic action.. (Farid, etal. ,1989-Braud etal,2000)..

Example of enzymes that could be detected in snakes venoms are; fibrinognolytic enzymes such; Alpha-fibrinogenases, Beta-fibrinogenases, and Gamma-fibrinogenases. Other enzymes that could be detected include plasminogen activator releasers; such as Ecarin., prothrombin activator,. prthrombinase complex formation inhibitors such as; Phospholipase A2,B,C and D, Factor X-activator., Factor V-activator, .Factor XI-activator, .Protein-C-activator, fibrinogenolysin.,Platelet aggregation inducers, either without coagulant activity, or with coagulant activity. ,Platelet aggregation inhibitors, such as alpha fibrinogenases or 5-Nucleotidase, or ADPase ,or fibrinogen receptor antagonists, Von Willebrand factor-dependent platelet aggregation inducers. Zinc metalloprotease ,which disrupt the endothelial lining of blood vessels causing spontaneous bleeding, hyaluronidases (spreading factor)., arginine esterase and, L-amino acid oxidase which is widely found in snake venoms, and is responsible for the yellow coloration of snake venom due to the presence of riboflavin as a prosthetic group(Ouyang, etal.,1992 – Adrian, etal.,1994- Ali etal,2000).

Most of these enzymes are hydrolytic in nature except L- amino acid oxidase that causes oxidative deamination of amino acids. It is also reported to play a role in inhibiting platelet aggregation, induction of apoptosis ,hemorrhagic effects, and cytotoxicity. (Bailey and Wilce,2001-Du and Clemeston, 2002).

Other enzymes present in snake venoms and considered as toxic elements include phosphodiesterase, phosphatases(acid and alkaline)., Cholinesterases, transaminases, proteases, esterases, 5-nucleotidase, ATPase, and R.N.Aase. However, non of these enzymes are responsible for the acute toxicity of snake venom (Halim, etal. ,1992).

Phospholipase A2 (PLA2). is one of the venom enzymes that catalyses the hydrolysis of fatty acid ester bounds and the phospholipids . The specificity of the enzyme is directed towards the site of the fatty acid at the B-position rather than to the type of fatty acid. It is believed that phaspholipase A2, is responsible for haemolysis produced by venoms. This may be due to direct action on red cell membrane or indirect action by cleavage of lecithin producing lysolecithin (a hemolytic factor).. (Rudrammaji etal,2001)..

Acetylcholine esterase hydrolyzes acetylcholine ester into choline and acetic acid. It has a direct action on heart and neuromuscular junction. It may also facilitate the distribution of more toxic components of venom into the victim’s tissues. It is found only in Elapidae and Hydrophidae venoms and never in Viperidae or Crotalidae venoms (Rochu etal, 2001).

Phosphatases, commonly found in different snake venoms, may render the prey helpless by depriving it from its immediate source of energy, ATP. Added to this is the marked vasodilator effect produced by these products, therefore participating in production of shock. Hyaluronidases usually hydrolyzes the gel between the cell spaces and fibers, thus reducing the viscosity of tissues, so spreading and facilitating the absorption of the venom from the site of envenomation and speed up the process of poisoning. Proteases are enzymes responsible for digestion of tissue proteins so, venoms rich in protease produce marked tissue destruction (Tan et al, 1989).

Study of different snake venom proteases may lead to utilization of some blood clotting factor activators in the treatment of some disease associated with defects in blood coagulation Arvin (ancord). ,a thrombin-like enzyme (Agkisacutacin). isolated from the venom of Agkistrodon acutus is now used successfully for the treatment of thrombo-embolic diseases(Li etal, 2000).

Recently, purification of factor X activators from snake venom has been achieved. The potential utilization of these activators in treatment of hemophilic patients was considered. Also a potent coagulant thrombin-like enzyme(cerastobin) was purified from Cerastes vipera venom and showed a weak platelet aggregatory effect. Similarly, Viperabin is another thrombin-like enzyme with a moderate platelet aggregatory effect was also purified from the venom of Cerastes vipra. Moreover, snake venoms contain many enzymes that hydrolyze phosphomonoester and phosphodiester bonds(Baily and wilce,2001).

Protein organic component of snake venoms :

The protein component of snake venoms comprise of 90-95% of its dry weight and are more important biologically than the non protein part(Kamignti etal., 1998)..

This protein component is further subdivided into enzymatic and non enzymatic proteins:

The non enzymatic protein:

The non enzymatic proteins are mainly neurotoxins and some non neurotoxins basic proteins .Neurotoxins are so termed because they produced paralysis or convulsions before death These neurotoxins may inhibit axonic or synaptic transmission, Elapidae and Hydrophiidae venoms act on acetylcholine receptor(post synaptic toxins)., Phospholipase A2 found in the venom of the Naja naja sputatrix was identified as an inhibitor of the muscarinic receptors(Sakai, etal. ,1995 Miyoshi and Tu, 1996).

While in Viperidae and Crotalidae there is only minimal amount of neurotoxins as shown by isolation of weak neurotoxins from Cerastes cerastes(Farid, etal. ,1986).

Instead, Viperidae and Crotalidae venoms contain other non neurotoxic basic proteins which comprise cardiotoxins, cytotoxins, and myotoxins which are basic proteins with 42 amino acid residues and three disulfide bonds. This bonding and small size gives it a very compact structure. The earliest visible, and ultimately most pronounced, damage occurs within the muscle cell, specifically in the sarcomplasmic reticulum membrane system. Another protein is recently purified from viper venom and is called, Increasing Capillary Permeability Protein(ICPP).which showed a strong homology to the endogenous vascular endothelial growth factor(VEGF)..This venom derived (ICPP). exerts its biological action(permeability and angiogenesis). through activation of (VEGF). receptor signaling(Ouyeng, etal. ,1992-Gasmi, et al 2002).

The peptides present in the snake venom are physiologically very active components and are classified into two type :-

 bradykinin potentiating peptides and

 Those inhibiting the conversion of angiotensin I to angiotensin II

These two systems are important physiologic regulators of the vascular and circulatory systems (Mc Giff and Nasjlatti, 1976).

Thanks a lot sir

This was really helpful

Snake venoms are one of potent reservoir of active compounds. Commonly they consits of proteases, hyaluronidase (Spreading factor- helps in the absorption of venom), coagulation factors, antimicrobial peptides, fibrinolytic enzymes etc.,.

These are some papers that may help you:

Serine protease isoforms of Deinagkistrodon acutus venom:

cloning, sequencing and phylogenetic analysis.

Isolation and characterization of hyaluronidase a “spreading factor”

from Indian cobra (Naja naja) venom

Characterization of venom (Duvernoy's

secretion) from twelve species of colubrid

Antibacterial activity of six novel peptides from Tityus discrepans scorpion

venom. A fluorescent probe study of microbial membrane Naþ

permeability changes

Taxonomic distribution and quantitative analysis of free purine

and pyrimidine nucleosides in snake venoms.

snakes and partial sequence of four venom

proteins

The main thing you should have to know is that the composition of snake venoms may be highly variable even in a single species, especially in Naja sp. Look at this paper, showing the differences observed in India in Naja naja. Greater differences in southest Asia and Africa as well, leading to different toxicological dominant properties ( neurotoxic vs vascular effects).

Meier, J. and J. White( 1995): Handbook of Clinical Toxicology of animal venoms and poisons. CRC Press