摘要
目的通过激光共聚焦拉曼光谱仪进行人牙周膜结构测定,探讨Ⅰ型胶原酶处理后牙周膜胶原纤维中胶原蛋白二级结构的变化。方法将人前磨牙牙根自颈部至根尖切分为3片2 mm薄片,选择根中部牙周膜样本进行实验。将牙周膜样本分为酶处理组和对照组,酶处理组样本在室温下进行10 mg/mLⅠ型胶原酶溶液浸泡2 h。两组样本依次进行拉曼光谱仪测定,获得拉曼光谱并进行峰值分析。结果获得正常和胶原酶处理后人牙周膜样本的拉曼光谱图以及胶原蛋白二级结构谱图。人牙周膜拉曼光谱在酰胺Ⅰ带、酰胺Ⅲ带、CH2、酪氨酸和苯丙氨酸都出现特征峰。胶原蛋白的二级结构的主链构象主要由酰胺Ⅰ带(1 600~1 700 cm-1)和酰胺Ⅲ带(1 200~1 350 cm-1)表征,特征峰位在胶原酶处理后出现偏移。对照组牙周膜酰胺Ⅲ带的高斯拟合胶原蛋白各二级结构相对含量百分比分别为:无规卷曲29%,α-螺旋61%,β-回折2%,β-折叠8%。胶原酶处理后酰胺Ⅲ带中α-螺旋的含量下降,无规卷曲、β-回折和β-折叠的含量上升。结论Ⅰ型胶原酶使牙周膜胶原蛋白降解,改变了蛋白的二级结构,可能与牙周膜生物力学性能下降有关。
Objective To investigate the changes of collagen secondary structure in collagen fibers of human periodontal ligament(PDL) treated with collagenase Ⅰ using Raman spectroscopy. Methods The human premolars were divided into three 2 mm slices from the neck to the apex. Experimental samples were selected from the PDL in the middle of the root. The samples of the same tooth were divided into the control group and the enzyme treatment group. Samples in the treatment group were soaked in 10 mg/mL type Ⅰ collagenase solution for 2 hours at room temperature. The samples in the two groups were detected by Raman spectroscopy. The Raman spectra were obtained, and the peak value was analyzed. Results Raman spectra of human PDL showed characteristic peaks in amide Ⅰ, amide Ⅲ, CH2, tyrosine, and phenylalanine. The main chain conformation of the secondary structure of collagen was mainly characterized by the amide Ⅰ band(1 600-1 700 cm-1) and the amide Ⅲ band(1 200-1 350 cm-1). Furthermore, the characteristic peak deviated after collagenase treatment. Comparatively, in the untreated group, the percentages of the secondary structure of collagen in the amide Ⅲ band were random curl 29%, α-helix 61%, β-turn 2%, and β-fold 8%. After collagenase treatment, the contents of α-helix decreased, while the contents of random coil, β-turn and β-fold increased. Conclusion Collagenase type Ⅰ can degrade the collagen of PDL and change the secondary structure of protein, which may be related to the decrease of biomechanical properties of PDL.
作者
刘懋
唐苗宁
管佳妮
谢理哲
吴斌
顾敏芬
严斌
LIU Mao;TANG Miaoning;GUAN Jiani;XIE Lizhe;WU Bin;GU Minfen;YAN Bin(Department of Orthodontics,the Affiliated Stomatological Hospital of Nanjing Medical University,Nanjing 210029,China)
出处
《口腔医学》
CAS
2021年第6期481-485,共5页
Stomatology
基金
国家自然科学基金(82071143,81571005)
江苏省重点研发计划专项资金(BE2018723)
江苏高校优势学科建设工程(PAPD,2018-87)。
关键词
胶原蛋白
牙周膜
Ⅰ型胶原酶
拉曼光谱
collagen
periodontal ligament
collagenase typeⅠ
Raman spectroscopy
