Center for Pheromone Technology, Department of Animal Science, Bharathidasan University, Tiruchirappalli, Tamilnadu, India 620 024.
Rapid Commun Mass Spectrom. 2010 Mar;24(6):721-8. doi: 10.1002/rcm.4437.
The role of pheromones and pheromone-binding proteins in the laboratory rat has been extensively investigated. However, we have previously reported that the preputial gland of the Indian commensal rat produces a variety of pheromonal molecules and preputial glands would seem to be the predominant source for pheromonal communication. The presence of pheromone-binding proteins has not yet been identified in the preputial gland of the Indian commensal rat; therefore, the experiments were designed to unravel the alpha(2u)-globulin (alpha2u) and its bound volatiles in the commensal rat. Total preputial glandular proteins were first fractionated by sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE) and subsequently analyzed by mass spectrometry. Further, we purified alpha2u and screened for the presence of bound pheromonal molecules with the aid of gas chromatography/mass spectrometry (GC/MS). A novel alpha2u was identified with a high score and this protein has not been previously described as present in the preputial gland of Indian commensal rats. This novel alpha2u was then characterized by tandem mass spectrometry (MS/MS). Peptides with m/z values of 969, 1192, 1303 and 1876 were further fragmented with the aid of MS/MS and generated de novo sequences which provided additional evidence for the presence of alpha2u in the preputial gland. Finally, we identified the presence of farnesol 1 and 2 bound to alpha2u. The present investigation confirms the presence of alpha2u (18.54 kDa) in the preputial gland of the Indian commensal rat and identifies farnesol 1 and 2 as probably involved in chemo-communication by the Indian commensal rat.
信息素和信息素结合蛋白在实验大鼠中的作用已得到广泛研究。然而，我们之前曾报道过，印度共生鼠的包皮腺会产生多种信息素分子，而包皮腺似乎是信息素交流的主要来源。目前尚未在印度共生鼠的包皮腺中发现信息素结合蛋白；因此，设计了实验以揭示印度共生鼠中的α(2u)-球蛋白（α2u）及其结合的挥发性物质。首先通过十二烷基硫酸钠/聚丙烯酰胺凝胶电泳（SDS-PAGE）对总包皮腺蛋白进行分级，然后通过质谱进行分析。此外，我们通过气相色谱/质谱（GC/MS）纯化α2u，并筛选结合的信息素分子。鉴定出一种新型α2u，得分很高，这种蛋白质以前未被描述为存在于印度共生鼠的包皮腺中。然后通过串联质谱（MS/MS）对这种新型α2u进行了表征。m/z 值为 969、1192、1303 和 1876 的肽进一步通过 MS/MS 进行碎片化，并生成从头序列，为包皮腺中存在α2u 提供了额外的证据。最后，我们鉴定出存在与α2u 结合的法呢醇 1 和 2。本研究证实了印度共生鼠包皮腺中存在α2u（18.54 kDa），并鉴定出法呢醇 1 和 2 可能参与印度共生鼠的化学通讯。
