The present study describes a reproducible and quantitative capillary zone electrophoresis (CZE) method, which leads to the separation of nine forms (native, oxidized and glycated) of human serum albumin (HSA). In an attempt to identify the different species separated by this CZE method, the capillary electrophoresis was coupled to mass spectrometry using a sheath liquid interface, an optimized capillary coating and a suitable CE running buffer. CE-MS analyses confirmed the heterogeneity of albumin preparation and revealed new truncated and modified forms such as Advanced Glycation End products (AGEs). Assignment of the CZE peaks was carried out using specific antibodies, carboxypeptidase A or sample reduction before or during the CE separation. Thus, five HSA forms were unambiguously identified. Using this CZE method several albumin batches produced by slightly different fractionation ways could be discriminated. Furthermore, analyses of HSA preparations marketed by five pharmaceutical industries revealed that two therapeutic albumins, including that marketed by LFB, contained the highest proportion of native form and lower levels of oxidized forms.
Keywords: 3-deoxyglucosone-derived lysine dimer 1,3-di(N(ɛ)-lysino)-4-(2,3,4-trihydroxybutyl)-imidazolium salt; 4-(2-hydroxyethyl)-1-piperazine-ethane-sulfonic acid; AGE; Advanced Glycation End product; Advanced Glycation End products; BGE; CE; CE-MS; CEL; CML; CPA; CZE; Capillary zone electrophoresis; DGH; DOLD; EOF; ESI; GH; GOLD; HEPES; HPC; HSA; HSA minus aspartic acid and alanine from the N-terminus; HSA minus leucine from the C-terminus; HSA+Cys; HSA+G; HSA+HCys; HSA-DA; HSA-L; HSA-SNO; HSA-SO(2)H; HSA-SO(3)H; HSA-SOH; HSA-sulfenic acid; HSA-sulfinic acid; HSA-sulfonic acid; Human serum albumin; IT; MGH; MOLD; MS; Mass spectrometry; N(ɛ)-(1-carboxyethyl)-lysine; N(ɛ)-carboxymethyl-lysine; N(δ)-(4-carboxy-4,6-dimethyl-5,6-dihydroxy-1,4,5,6-tetrahydropyrimidin-2-yl)-ornithine; N(δ)-(5-hydro-4-imidazolon-2-yl)-ornithine; N(δ)-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine; N(δ)-[5-(2,3,4-trihydroxybutyl)-5-hydro-4-imidazolon-2-yl]-ornithine; PEO; PMMA; SDS; TBS; THP; TIC; background electrolyte; capillary electrophoresis; capillary electrophoresis-mass spectrometry; capillary zone electrophoresis; carboxypeptidase A; cysteinylated HSA; electroosmotic flow; electrospray ionization; glutathionylated HSA; glyoxal-derived lysine dimer, 1,3-di(N(ɛ)-lysino)-imidazolium salt; homocysteinylated HSA; human serum albumin; hydroxypropyl cellulose; ion trap; mass spectrometry; methylglyoxal-derived lysine dimer, 1,3-di(N(ɛ)-lysino)-4-methyl-imidazolium salt; nitrosylated HSA; polyethylene oxide; polymethylmethacrylate; sodium dodecyl sulftate; total ion current; tris-buffered saline.
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