Immunochemistry Laboratory, Butantan Institute, Av. Prof. Vital Brazil, 1500, CEP 05503-900, São Paulo, Brazil.
Toxicon. 2012 Jan;59(1):124-31. doi: 10.1016/j.toxicon.2011.11.001. Epub 2011 Nov 10.
Snakebite envenomation is considered a highly relevant public health hazard in South America, having an impact in terms of mortality and morbidity. In Brazil, Bothrops (sensu latu) poisoning is responsible for 90% of the snakebites and in patients treated at the Vital Brazil Hospital (Butantan Institute) this index reaches 97.5%. The objective of the present study was to analyze more specifically the ability of the antibothropic antivenom, produced by the Butantan Institute, São Paulo, Brazil, to neutralize metallo-and serine peptidases, known as the major toxins present in Bothrops jararaca venom. A set of Fret peptides (Free Ressonance Energy Transfer) was studied using the BjV (B. jararaca venom) and site-directed inhibitors PMSF, EDTA and 1,10-phenanthroline. Two substrates were reached to be used as specific tools for studies with metallo peptidases, Abz-FASSAQ-EDDnp, and the serine peptidases, Abz-RPPGFSPFRQ-EDDnp. In disagreement with the literature, the use of both substrates and the antibothropic serum showed a weak neutralization of the serine peptidases present in this venom and a strong neutralization of the metallo peptidases. In order to investigate possible mechanisms of action that have not yet been described for the serine peptidases from the BjV, the present study shows for the first time a new tyrosine-specific chymotrypsin-like and angiotensin-degrading serine peptidase activity, that was partially blocked by the antibothropic serum. In conclusion, the antivenom presented a good neutralization of metallo peptidases but not of serine peptidases, indicating that further studies about serine peptidases immunogenicity are necessary to improve the antibothropic serum.
蛇伤被认为是南美洲一个非常重要的公共卫生危害，对死亡率和发病率都有影响。在巴西，90%的蛇伤是由 Bothrops（广义）中毒引起的，而在 Vital Brazil 医院（Butantan 研究所）治疗的患者中，这一指数达到 97.5%。本研究的目的是更具体地分析由巴西圣保罗 Butantan 研究所生产的抗 Bothrops 蛇毒血清中和金属和丝氨酸肽酶的能力，已知这些酶是 Bothrops jararaca 毒液中的主要毒素。使用 BjV（B. jararaca venom）和定点抑制剂 PMSF、EDTA 和 1,10-phenanthroline 研究了一组 Fret 肽（Free Ressonance Energy Transfer）。两种底物被用于作为研究金属肽酶的特定工具，Abz-FASSAQ-EDDnp 和丝氨酸肽酶，Abz-RPPGFSPFRQ-EDDnp。与文献不一致的是，使用这两种底物和抗 Bothrops 血清对这种毒液中的丝氨酸肽酶表现出较弱的中和作用，而对金属肽酶则表现出较强的中和作用。为了研究 BjV 中的丝氨酸肽酶尚未描述的可能作用机制，本研究首次显示了一种新的酪氨酸特异性糜蛋白酶样和血管紧张素降解丝氨酸肽酶活性，该活性被抗 Bothrops 血清部分阻断。总之，抗蛇毒血清对金属肽酶有很好的中和作用，但对丝氨酸肽酶没有，这表明需要进一步研究丝氨酸肽酶的免疫原性，以改进抗 Bothrops 血清。
