HSP-1/2, a major horse seminal plasma protein, acts as a chaperone against oxidative stress.

The major protein of equine seminal plasma, HSP-1/2 exhibits chaperone-like activity and protects a variety of target proteins against thermal and chemical stress conditions. Here, we show that HSP-1/2 is able to protect enzymes such as alcohol dehydrogenase and glucose-6-phosphate dehydrogenase against H2O2 induced stress, clearly demonstrating that HSP-1/2 acts as a chaperone against oxidative stress. Further, the present studies show that HSP-1/2 also inhibits lipid (linoleic acid) peroxidation by hydroxyl radicals in vitro. These results are of great significance considering that so far limited or no antioxidative mechanism has been reported to be present in the mammalian spermatozoa that prevents lipid peroxidation which is detrimental to the motility and functioning of spermatozoa.