质谱法测定4种真菌毒素与载体蛋白偶联物的结合比

采用基质辅助激光解吸-电离飞行时间质谱法(matrix-assisted laser desorption/ionization time-of-flight mass spectrometry，MALDI-TOFMS)对由3种真菌毒素伏马菌素B1(FB1)、赭曲霉毒素A(OTA)、脱氧雪腐镰刀菌烯醇(DON)与两种载体蛋白卵清白蛋白(OVA)、血清白蛋白(BSA)分别偶联制备得到的4种小分子-载体蛋白偶联物FB1-OVA、FB1-BSA、OTA-BSA、DON-OVA的偶联结合比进行测定，并与紫外吸收光谱法进行比较。基质辅助激光解吸-电离飞行时间质谱法测得偶联物FB1-OVA、FB1-BSA、OTA-BSA、DON-OVA的结合比分别为5:1、11:1、3:1、0；紫外吸收光谱法测得OTA-BSA的结合比为4.4:1，DON-OVA的结合比为3.4:1，无法测定FB1-OVA、FB1-BSA结合比。

Determination of Coupling Ratios of Four Mycotoxins-Carrier Protein Conjugates by Mass Spectrometry

Three mycotoxins including fumonisin B1(FB1),ochrotoxin A(OTA) and deoxynivalenol(DON) were coupled with two carrier proteins such as ovalbumin(OVA) and bovine serum albumin(BSA),respectively.Four small molecule-carrier protein conjugates(FB1-OVA,FB1-BSA,OTA-BSA and DON-OVA) were prepared.The coupling ratios of the conjugates were determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOFMS) and ultraviolet(UV) absorption spectroscopy,respectively.The coupling ratios of FB1-OVA,FB1-BSA,OTA-BSA and DON-OVA were 5:1,11:1,3:1 and 0,respectively as determined by MALDI-TOFMS.However,the coupling ratios of OTA-BSA and DON-OVA determined by UV absorption spectroscopy were 4.4:1 and 3.4:1,respectively.The coupling ratios of FB1-OVA and FB1-BSA could not be determined by UV absorption spectroscopy.