Tx2-6 is a toxin found in the venom of the
Brazilian wandering spider, ''
Phoneutria nigriventer''
(Keyserling Keyserling is the surname of several members of the noble House of Keyserlingk:
* Alexander Keyserling (1815–1891), Russian geologist, paleontologist, botanist and zoologist
* Eugen von Keyserling (1833–1889), German arachnologist
* Hermann ...
). It is a
peptide of 48 residues, molecular weight 5291.3. This peptide is cleaved from a longer precursor with a
signal peptide
A signal peptide (sometimes referred to as signal sequence, targeting signal, localization signal, localization sequence, transit peptide, leader sequence or leader peptide) is a short peptide (usually 16-30 amino acids long) present at the N-ter ...
and a glutamine-rich
propeptide
A protein precursor, also called a pro-protein or pro-peptide, is an inactive protein (or peptide) that can be turned into an active form by post-translational modification, such as breaking off a piece of the molecule or adding on another molecule ...
. It can cause
priapism
Priapism is a condition in which a penis remains erect for hours in the absence of stimulation or after stimulation has ended. There are three types: ischemic (low-flow), nonischemic (high-flow), and recurrent ischemic (intermittent). Most cases ...
. Tests on rats indicate that the toxin causes
nitric oxide
Nitric oxide (nitrogen oxide or nitrogen monoxide) is a colorless gas with the formula . It is one of the principal oxides of nitrogen. Nitric oxide is a free radical: it has an unpaired electron, which is sometimes denoted by a dot in its che ...
release, and its effect on erection is blocked by the
nitric oxide synthase inhibitor
L-NAME. However, it fully restored erectile function in rats developing
hypertension
Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high bl ...
due to injection of
deoxycorticosterone Deoxycorticosterone (DOC), or desoxycorticosterone, may refer to:
* 11-Deoxycorticosterone (21-hydroxyprogesterone)
* 21-Deoxycorticosterone (11β-hydroxyprogesterone)
See also
* Deoxycortisol
* Deoxycortisone
* 11-Hydroxyprogesterone
{{Che ...
acetate. A study is underway at the
Medical College of Georgia looking at possible uses for the chemical in
erectile dysfunction
Erectile dysfunction (ED), also called impotence, is the type of sexual dysfunction in which the penis fails to become or stay erect during sexual activity. It is the most common sexual problem in men.Cunningham GR, Rosen RC. Overview of male ...
medication. Scientists and Gregory Ochs (Dobbs 2) are collaborating on this study.
See also
*
Pharmacology
Pharmacology is a branch of medicine, biology and pharmaceutical sciences concerned with drug or medication action, where a drug may be defined as any artificial, natural, or endogenous (from within the body) molecule which exerts a biochemica ...
*
Spiders
Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species dive ...
References
External links
Spider venom for Erectile Dysfunction(27 September 2009)
Spider toxins
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