Purification and identification of sulfated Lewis X binding proteins in boar sperm

Lewis X;oviduct reservoir;sperm;lactadherin;glycan

Pedroso De Barros Correa Da Silva, Elena

关键词: Lewis X;    oviduct reservoir;    sperm;    lactadherin;    glycan;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/46796/Elena_Pedroso%20De%20Barros%20Correa%20Da%20Silva.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

After insemination, sperm can be held in the isthmus region of the oviduct forming a reservoir. There is evidence that formation of the oviduct sperm reservoir is mediated, at least partially, by sperm recognition of carbohydrate structures present on the oviduct epithelium. In pigs, previous studies have proposed that glycans containing mannose termini are the structures recognized by the sperm protein AQN1. However, using a novel screening approach, our group has established that pig sperm bind preferentially to glycans containing the Lewis X trisaccharide (LeX) or multi-antennary sialylated N-acetyllactosamine motifs and much less to motifs with terminal mannose. Based on these findings, the aim of this PhD dissertation was to identify sperm molecule/s involved in sperm binding to the sulfated version of LeX (sLeX, a LeX version that binds sperm with high affinity) that mediate sperm adhesion to the oviduct epithelium. From this work it was possible to detect multiple sLeX and SiLN putative receptors in epididymal and ejaculated sperm; furthermore, some of these receptors have overlapping characteristics that include comparable molecular weights and requirement of Ca2+ for adhesion (Chapter 3). Investigation of sLeX receptors in ejaculated sperm by affinity chromatography identified the membrane protein AQN1, suggesting that this protein may also recognize glycans with sLeX termini other than mannose (Chapter 4). A main finding of this work was the establishment of the sperm membrane protein lactadherin as one receptor for the oviduct epithelium; incubation of oviduct cell aggregates with the recombinant protein significantly inhibited sperm adhesion (Chapter 4). Furthermore, additional studies using epididymal sperm, instead of ejaculated sperm, also identified ADAM5 as a receptor for sLeX (Chapter 5). In summary, the results illustrated in this PhD dissertation prove that distinct proteins are involved in sperm binding to sLeX motifs and proposes that an adhesion protein complex including lactadherin and ADAM5 binds the oviduct.