Garcia Eva M, Vázquez Juan M, Calvete Juan J, Sanz Libia, Caballero Ignacio, Parrilla Inmaculada, Gil Maria A, Roca Jordi, Martinez Emilio A
Departamento de Medicina y Cirugía Animal, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30071 Murcia, Spain.
J Androl. 2006 May-Jun;27(3):434-43. doi: 10.2164/jandrol.05170. Epub 2005 Dec 8.
To dissect the protective activity of PSP-I/PSP-II, the effect of the isolated subunits PSP-I and PSP-II and their affinity-purified tryptic peptide and glycan fractions on the viability, mitochondrial activity, and motility of highly diluted boar spermatozoa was investigated. High dilution exerted a negative effect on control spermatozoa. Incubation of spermatozoa with PSP-I/PSP-II or with its PSP-II subunit had a protective effect on sperm functionality, high mitochondrial membrane potential, and sperm motility. These effects were less pronounced when spermatozoa were incubated with the PSP-I subunit. It was noteworthy that motility was abolished by incubation of spermatozoa with isolated PSP-I. Trypsin-degraded PSP-I/PSP-II, PSP-I, and PSP-II reproduced the effects of the native proteins. Incubating spermatozoa with the glycan-depleted tryptic-peptide fraction of PSP-I/PSP-II for 5 hours preserved a higher percentage of viable spermatozoa than when sperm was incubated for the same time with the native heterodimer, trypsin-digested PSP-I/PSP-II, the glycan fraction or without added proteins. However, sperm motility decreased as the concentration of added peptide fraction increased. On the other hand, spermatozoa incubated with the glycan fraction showed lower values than spermatozoa incubated with the peptide fraction. We concluded that the subunits of the PSP-I/PSP-II heterodimeric spermadhesin exert different activities on sperm functions. The finding that the beneficial effect of the native PSP-I/PSP-II on the functionality of highly diluted boar spermatozoa is largely preserved in its isolated PSP-II subunit and does not appear to require the glycan moiety points to a peptide moiety as a potential sperm function-preserving additive of highly diluted boar spermatozoa.
为剖析PSP-I/PSP-II的保护活性，研究了分离的亚基PSP-I和PSP-II及其亲和纯化的胰蛋白酶肽段和聚糖组分对高度稀释的公猪精子活力、线粒体活性和运动能力的影响。高度稀释对对照精子产生负面影响。精子与PSP-I/PSP-II或其PSP-II亚基孵育对精子功能、高线粒体膜电位和精子运动能力具有保护作用。当精子与PSP-I亚基孵育时，这些作用不太明显。值得注意的是，精子与分离的PSP-I孵育会导致运动能力丧失。胰蛋白酶降解的PSP-I/PSP-II、PSP-I和PSP-II重现了天然蛋白质的作用。将精子与PSP-I/PSP-II的聚糖缺失胰蛋白酶肽段孵育5小时，与精子与天然异二聚体、胰蛋白酶消化的PSP-I/PSP-II、聚糖组分或不添加蛋白质孵育相同时间相比，能保留更高比例的活精子。然而，随着添加肽段浓度的增加，精子运动能力下降。另一方面，与聚糖组分孵育的精子显示的值低于与肽段组分孵育的精子。我们得出结论，PSP-I/PSP-II异二聚体精子黏附素的亚基对精子功能发挥不同的活性。天然PSP-I/PSP-II对高度稀释的公猪精子功能的有益作用在其分离的PSP-II亚基中基本保留，并且似乎不需要聚糖部分，这表明肽部分是高度稀释的公猪精子潜在的精子功能保护添加剂。
