The peptide tangles, discovered in 2007, are called semen enhancer of viral infection (SEVI). SEVI is a formed tangle of peptides on the surface of sperm cells which is called amyloid fibers. Those fibers have been indicated in other long term disease issues including Alzheimer’s and Parkinson’s and Type -2 diabetes.

The SEVI are called PAP248-286 by U-M researchers.

Researchers found that SEVI made it easier for HIV to infect other cells, and now U-M researchers have a slightly better idea of how.

Ayyalusamy Ramamoorthy, a U-M researcher and co-author of the studies, says the way the amyloid fibers spread out on the surface of the sperm cell aids the transmission of HIV as it “shocks” the surface of the cell, creating a structural change — in essence a dimple, where the virus can latch on.

HIV uses a similar “dimple” on white blood cells called a CCR-5 receptor site to infect those cells. An American man in Berlin has been virus free for over two years because doctors did a bone marrow transplant on him replacing his immune system with white blood cells that naturally did not have CCR-5 receptors.

The results were published Nov. 17 in Journal of the American Chemical Society and Nov. 4 in Biophysical Journal. The research was funded by a grant from the National Institutes of Health.