Lapolla A, Gerhardinger C, Pelli B, Sturaro A, Del Favero E, Traldi P, Crepaldi G, Fedele D
Institute of Internal Medicine, University of Padova, Italy.
Diabetes. 1990 Jan;39(1):57-61. doi: 10.2337/diacare.39.1.57.
Accumulation of brown products in long-lived proteins might be an important factor in determining long-term diabetic complications. Fluorescent chromophore 2-(2-furoyl)-4-(5)-(2-furanyl)-1H-imidazole (FFI), isolated from hydrolyzed brown products synthesized in vitro, was proposed as a specific brown product responsible for functional and structural changes in long-lived proteins. In this study, an attempt was made to demonstrate by means of collision spectroscopy the presence of FFI in collagen samples taken from diabetic rats. Diabetic rat collagen samples showed mean values of absorbance per milligram of 4-hydroxy-L-proline significantly higher than those observed in nondiabetic rats, suggesting higher FFI levels. Surprisingly, all collagen samples from diabetic and nondiabetic rats gave collision spectra in which no peak diagnostic of FFI presence was observed. These data suggest that the absorbance level observed in diabetic rats is not due to the presence of FFI but to structurally related compounds, which are being investigated by means of mass spectrometry.
长寿命蛋白质中棕色产物的积累可能是决定糖尿病长期并发症的一个重要因素。从体外合成的水解棕色产物中分离出的荧光发色团2-(2-呋喃甲酰基)-4-(5)-(2-呋喃基)-1H-咪唑(FFI)，被认为是导致长寿命蛋白质功能和结构变化的一种特定棕色产物。在本研究中，试图通过碰撞光谱法证明从糖尿病大鼠获取的胶原蛋白样品中存在FFI。糖尿病大鼠胶原蛋白样品每毫克4-羟基-L-脯氨酸的吸光度平均值显著高于非糖尿病大鼠，提示FFI水平更高。令人惊讶的是，来自糖尿病和非糖尿病大鼠的所有胶原蛋白样品给出的碰撞光谱中均未观察到可诊断FFI存在的峰。这些数据表明，在糖尿病大鼠中观察到的吸光度水平并非由于FFI的存在，而是由于结构相关化合物，目前正在通过质谱法对其进行研究。
