Structural determination of the conjugate of human serum albumin with a mitomycin C derivative, KW-2149, by matrix-assisted laser desorption/ionization mass spectrometry.
A new mitomycin C derivative, KW-2149, is known to form a covalent conjugate with human serum albumin (HSA). This conjugate exhibits 1/20 of the anticellular activity of unconjugated KW-2149. Structural studies of this conjugate were carried out using a combination of enzymatic digestion, high-performance liquid chromatography (HPLC), and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The tryptic peptide T5 (residues 21-41) was the only peptide found to be modified by KW-2149 moieties, the [(gamma-L-glutamylamino)ethyl]thio group or the (2-aminoethyl)thio group, through a disulfide bond. Although the latter peptide lost its mitomycin C moiety in the course of tryptic digestion, these data strongly suggest that KW-2149 was bound to Cys-34, the only free cysteine on HSA.
Yasuzawa
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T
Laboratory of Structural Biology, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.
Tomer
K B
KB
D000595:Amino Acid Sequence; D000970:Antineoplastic Agents / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D016685:Mitomycin / Q000737:chemistry; D008937:Mitomycins; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D012709:Serum Albumin / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000970:Antineoplastic Agents; D008937:Mitomycins; D012709:Serum Albumin; C057625:KW 2149; D016685:Mitomycin