Department for Orthodontics, Center for Dentistry, Oral Medicine and Craniomaxillofacial Surgery, University Medical Center, Georg August University, Robert-Koch-Str. 40, 37075, Göttingen, Germany.
Max Planck Institute for Biophysical Chemistry, Bioanalytical Mass Spectrometry Group, Am Fassberg 11, 37077, Goettingen, Germany.
Clin Oral Investig. 2018 Apr;22(3):1375-1384. doi: 10.1007/s00784-017-2213-0. Epub 2017 Oct 9.
Gingival crevicular fluid (GCF), the inflammatory infiltrate within the crevicular sulcus, is of great importance for diverse processes in the oral cavity and has a high impact in oral sciences. It is assumed to serve as a source of biomarkers for systemic or periodontal diseases and mediators of orthodontic tooth movement. In order to characterize the protein content of the GCF in an unbiased and complete approach, we employed mass spectrometry (MS), which allows not only the identification, but also the quantification of these proteins. In samples obtained from patients suffering from periodontitis, this method is often limited due to the presence of highly abundant serum albumin deriving from serum. The aim of this investigation was to employ a protein precipitation procedure for the efficient depletion of serum albumin from GCF samples.
GFC samples collected from five adult periodontitis patients were fractionated by trichloroacetic acid/acetone precipitation and the resulting soluble and pelleted fractions were analyzed by SDS-PAGE and high-resolution mass spectrometry.
Trichloroacetic acid/acetone precipitation was successfully employed as a protein precipitation procedure for the efficient depletion of serum albumin from GCF samples. Careful analysis revealed that the precipitation step reduced the serum albumin content efficiently, and increased subsequent protein identifications by 32%. Three hundred seventeen proteins could only be identified with this new approach.
The increased coverage of the GCF proteome will help improve our understanding of molecular mechanisms in the periodontium during pathogenesis of periodontitis.
Our new albumin depletion strategy combined with high-resolution mass spectrometry can be used to effectively monitor the molecular signals of the periodontium.
龈沟液（GCF）是龈沟内的炎症浸润物，对口腔内的多种过程都非常重要，并且对口腔科学有很大的影响。它被认为是系统性或牙周疾病生物标志物的来源，也是正畸牙齿移动的介质。为了以无偏和完整的方式描述 GCF 的蛋白质含量，我们采用了质谱（MS），该方法不仅可以识别这些蛋白质，还可以对其进行定量。在患有牙周炎的患者的样本中，由于存在大量源自血清的白蛋白，该方法通常受到限制。本研究的目的是采用蛋白质沉淀程序从 GCF 样本中有效去除血清白蛋白。
从五名成年牙周炎患者中收集 GFC 样本，用三氯乙酸/丙酮沉淀进行分级，然后对所得可溶和沉淀部分进行 SDS-PAGE 和高分辨率质谱分析。
三氯乙酸/丙酮沉淀成功地用作从 GCF 样本中有效去除血清白蛋白的蛋白质沉淀程序。仔细分析表明，沉淀步骤可有效降低血清白蛋白的含量，并使后续蛋白质鉴定增加 32%。通过这种新方法仅可鉴定 317 种蛋白质。
增加 GCF 蛋白质组的覆盖范围将有助于提高我们对牙周炎发病机制期间牙周组织中分子机制的理解。
我们的新白蛋白耗竭策略与高分辨率质谱相结合，可用于有效监测牙周组织的分子信号。
