Larjava H, Uitto V J, Haapasalo M, Heino J, Vuento M
Scand J Dent Res. 1987 Aug;95(4):308-14. doi: 10.1111/j.1600-0722.1987.tb01846.x.
Degradation of fibronectin (FN) by subgingival and supragingival plaque and Bacteroides gingivalis (Bg) was studied in vitro. The degradation of FN by both types of plaque was relatively rapid, continuous but incomplete. Some differences were found between supra- and subgingival samples. Supragingival plaque extracts produced several FN fragments of 110-180 kd during short incubations of 15-60 min. The predominant fragment after overnight incubation was a 110 kd polypeptide. With subgingival plaque extract a more extensive degradation of FN was noted. The main degradation product was a 120 kd fragment after overnight incubation. Several peptide fragments were released from fibronectin by Bg extracts. Their molecular size was different from those produced by trypsin, elastase or dental plaque. When cell extracts of Bg were fractionated by high performance liquid chromatography, three separate peaks of fibronectin degrading activity were obtained. Two of those peaks also contained trypsin-like enzyme activity. The degradation of fibronectin and the subsequent formation of biologically active peptides may have many effects in periodontal pockets. These may include modifying effects on plaque growth and wound healing.
在体外研究了龈下和龈上菌斑以及牙龈拟杆菌（Bg）对纤连蛋白（FN）的降解作用。两种类型的菌斑对FN的降解相对较快、持续但不完全。在龈上和龈下样本之间发现了一些差异。龈上菌斑提取物在15 - 60分钟的短时间孵育期间产生了几种110 - 180kd的FN片段。过夜孵育后的主要片段是110kd的多肽。对于龈下菌斑提取物，观察到FN有更广泛的降解。过夜孵育后的主要降解产物是120kd的片段。Bg提取物从纤连蛋白中释放出几个肽片段。它们的分子大小与胰蛋白酶、弹性蛋白酶或牙菌斑产生的不同。当Bg的细胞提取物通过高效液相色谱法进行分离时，获得了三个单独的纤连蛋白降解活性峰。其中两个峰也含有类胰蛋白酶活性。纤连蛋白的降解以及随后生物活性肽的形成可能在牙周袋中有许多影响。这些可能包括对菌斑生长和伤口愈合的调节作用。
