Tags

Type your tag names separated by a space and hit enter

Venomics of Naja sputatrix, the Javan spitting cobra: A short neurotoxin-driven venom needing improved antivenom neutralization.
J Proteomics. 2017 03 22; 157:18-32.JP

Abstract

The venom proteome of Naja sputatrix (Javan spitting cobra) was elucidated through reverse-phase HPLC, nano-ESI-LCMS/MS and data mining. A total of 97 distinct protein forms belonging to 14 families were identified. The most abundant proteins are the three-finger toxins (3FTXs, 64.22%) and phospholipase A2 (PLA2, 31.24%), followed by nerve growth factors (1.82%), snake venom metalloproteinase (1.33%) and several proteins of lower abundance (<1%) including a variety of venom enzymes. At subproteome, the 3FTx is dominated by cytotoxins (48.08%), while short neurotoxins (7.89%) predominate over the long neurotoxins (0.48%) among other neurotoxins of lesser toxicity (muscarinic toxin-like proteins, 5.51% and weak neurotoxins, 2.26%). The major SNTX, CTX and PLA2 toxins were isolated with intravenous median lethal doses determined as 0.13, 1.06 and 0.50μg/g in mice, respectively. SABU, the Indonesia manufactured homologous tri-specific antivenom could neutralize the CTX and PLA2 fraction with moderate potency (potency=0.14-0.16mg toxin per ml antivenom). The SNTX, however, was very poorly neutralized with a potency level of 0.034mg/ml, indicating SNTX as the main limiting factor in antivenom neutralization. The finding helps elucidate the inferior efficacy of SABU reported in neutralizing N. sputatrix venom, and supports the call for antivenom improvement.

BIOLOGICAL SIGNIFICANCE

The Javan spitting cobra, Naja sputatrix is by itself a unique species and should not be confused as the equatorial and the Indochinese spitting cobras. The distinction among the spitting cobras was however unclear prior to the revision of cobra systematics in the mid-90's, and results of some earlier studies are now questionable as to which species was implicated back then. The current study successfully profiled the venom proteome of authenticated N. sputatrix, and showed that the venom is made up of approximately 64% three-finger toxins (including neurotoxins and cytotoxins) and 31% phospholipases A2 by total venom proteins. The findings verified that the paralyzing components in the venom i.e. neurotoxins are predominantly the short-chain subtype (SNTX) far exceeding the long-chain subtype (LNTX) which is more abundant in the venoms of monocled cobra and Indian common cobra. The neurotoxicity of N. sputatrix venom is hence almost exclusively SNTX-driven, and effective neutralization of the SNTX is the key to early reversal of paralysis. Unfortunately, as shown through a toxin-specific assay, the immunological neutralization of the SNTX using the Indonesian antivenom (SABU) was extremely weak, implying that SABU has limited therapeutic efficacy in treating N. sputatrix envenomation clinically. From the practical standpoint, actions need to be taken at all levels from laboratory to production and policy making to ensure that the shortcoming is overcome.

Authors+Show Affiliations

Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia. Electronic address: tanngethong@yahoo.com.sg.Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia. Electronic address: tanchoohock@gmail.com.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

28159706

Citation

Tan, Nget Hong, et al. "Venomics of Naja Sputatrix, the Javan Spitting Cobra: a Short Neurotoxin-driven Venom Needing Improved Antivenom Neutralization." Journal of Proteomics, vol. 157, 2017, pp. 18-32.
Tan NH, Wong KY, Tan CH. Venomics of Naja sputatrix, the Javan spitting cobra: A short neurotoxin-driven venom needing improved antivenom neutralization. J Proteomics. 2017;157:18-32.
Tan, N. H., Wong, K. Y., & Tan, C. H. (2017). Venomics of Naja sputatrix, the Javan spitting cobra: A short neurotoxin-driven venom needing improved antivenom neutralization. Journal of Proteomics, 157, 18-32. https://doi.org/10.1016/j.jprot.2017.01.018
Tan NH, Wong KY, Tan CH. Venomics of Naja Sputatrix, the Javan Spitting Cobra: a Short Neurotoxin-driven Venom Needing Improved Antivenom Neutralization. J Proteomics. 2017 03 22;157:18-32. PubMed PMID: 28159706.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Venomics of Naja sputatrix, the Javan spitting cobra: A short neurotoxin-driven venom needing improved antivenom neutralization. AU - Tan,Nget Hong, AU - Wong,Kin Ying, AU - Tan,Choo Hock, Y1 - 2017/01/31/ PY - 2016/12/25/received PY - 2017/01/21/revised PY - 2017/01/30/accepted PY - 2017/2/6/pubmed PY - 2017/12/1/medline PY - 2017/2/5/entrez SP - 18 EP - 32 JF - Journal of proteomics JO - J Proteomics VL - 157 N2 - : The venom proteome of Naja sputatrix (Javan spitting cobra) was elucidated through reverse-phase HPLC, nano-ESI-LCMS/MS and data mining. A total of 97 distinct protein forms belonging to 14 families were identified. The most abundant proteins are the three-finger toxins (3FTXs, 64.22%) and phospholipase A2 (PLA2, 31.24%), followed by nerve growth factors (1.82%), snake venom metalloproteinase (1.33%) and several proteins of lower abundance (<1%) including a variety of venom enzymes. At subproteome, the 3FTx is dominated by cytotoxins (48.08%), while short neurotoxins (7.89%) predominate over the long neurotoxins (0.48%) among other neurotoxins of lesser toxicity (muscarinic toxin-like proteins, 5.51% and weak neurotoxins, 2.26%). The major SNTX, CTX and PLA2 toxins were isolated with intravenous median lethal doses determined as 0.13, 1.06 and 0.50μg/g in mice, respectively. SABU, the Indonesia manufactured homologous tri-specific antivenom could neutralize the CTX and PLA2 fraction with moderate potency (potency=0.14-0.16mg toxin per ml antivenom). The SNTX, however, was very poorly neutralized with a potency level of 0.034mg/ml, indicating SNTX as the main limiting factor in antivenom neutralization. The finding helps elucidate the inferior efficacy of SABU reported in neutralizing N. sputatrix venom, and supports the call for antivenom improvement. BIOLOGICAL SIGNIFICANCE: The Javan spitting cobra, Naja sputatrix is by itself a unique species and should not be confused as the equatorial and the Indochinese spitting cobras. The distinction among the spitting cobras was however unclear prior to the revision of cobra systematics in the mid-90's, and results of some earlier studies are now questionable as to which species was implicated back then. The current study successfully profiled the venom proteome of authenticated N. sputatrix, and showed that the venom is made up of approximately 64% three-finger toxins (including neurotoxins and cytotoxins) and 31% phospholipases A2 by total venom proteins. The findings verified that the paralyzing components in the venom i.e. neurotoxins are predominantly the short-chain subtype (SNTX) far exceeding the long-chain subtype (LNTX) which is more abundant in the venoms of monocled cobra and Indian common cobra. The neurotoxicity of N. sputatrix venom is hence almost exclusively SNTX-driven, and effective neutralization of the SNTX is the key to early reversal of paralysis. Unfortunately, as shown through a toxin-specific assay, the immunological neutralization of the SNTX using the Indonesian antivenom (SABU) was extremely weak, implying that SABU has limited therapeutic efficacy in treating N. sputatrix envenomation clinically. From the practical standpoint, actions need to be taken at all levels from laboratory to production and policy making to ensure that the shortcoming is overcome. SN - 1876-7737 UR - https://www.unboundmedicine.com/medline/citation/28159706/Venomics_of_Naja_sputatrix_the_Javan_spitting_cobra:_A_short_neurotoxin_driven_venom_needing_improved_antivenom_neutralization_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S1874-3919(17)30032-5 DB - PRIME DP - Unbound Medicine ER -