At last!
Scientists are getting closer to developing a new kind of reversible male contraceptive that doesn't produce any hormonal side effects.
While a commercial drug could still be some way off, the researchers have managed to isolate a key enzyme found only in sperm. Now that they've identified it and can manufacture this enzyme, the team hopes to target it with a range of drug candidates. With the right drug, it should be possible to decrease sperm motility – their ability to swim – which could prevent sperm from egg fertilisation.
"The milestone reached is the production and isolation of a full-length, active kinase enzyme in sufficient quantities to conduct drug screens," said researcher John Herr from the University of Virginia School of Medicine. "Isolation of an active, full-length form of this enzyme allows us to test drugs that bind to the entire surface of the enzyme so that we can identify inhibitors that may exert a selective action on sperm."
The enzyme in question – called testis-specific serine/threonine kinase 2 (TSSK2) – is unique to the testes, and also appears to only be involved in the final stage of sperm production. That's important, the researchers say, because it makes it more likely that any drug candidate that successfully targets the enzyme won't produce any side effects elsewhere in the body.
