Determination of XXXX adducts to human serum albumin.

@entity10725 @entity47372 @entity1522
@entity10725 ( @entity47372 ) is a highly sensitizing industrial chemical that is known to covalently bind to endogenous proteins. The aim of this study was to determine the binding sites of @entity47372 to human serum albumin (HSA). Conjugates between HSA and @entity47372 , at two different molar ratios, were synthesized under physiological conditions. The conjugates were digested with trypsin and Pronase E to obtain specific peptides and @entity1522 , which were separated by liquid chromatography (LC). Fractions containing modified peptides were detected through quantification of hydrolysable @entity47372 using LC coupled to a triple quadrupole mass spectrometer with electrospray ionization. Modified residues in albumin were identified by sequence analyses using nanoelectrospray quadrupole time-of-flight mass spectrometry. A total of 36 @entity47372 adducts were found in the HSA- @entity47372 conjugate with 10 times molar excess of added @entity47372 . In the conjugate with a molar ratio of 1:0.1 of added @entity47372 , seven @entity47372 adducts were found bound to Lys(137) (domain IB), Lys(190), Lys(199) and Lys(212) (domain IIA), Lys(351) (domain IIB), and Lys(432) and Lys(436) (domain IIIA). Moreover, several of these adducted albumin peptides were detected in nasal lavage fluid from one volunteer exposed to @entity47372 . The binding sites of @entity47372 to HSA have been determined, thus identifying potential allergenic chemical structures. This knowledge generates the possibility of developing methods for the biological monitoring of @entity47372 exposure by analysing tryptic peptides including these binding sites.
