title: Covalent core-shell architecture of hemoglobin and human serum albumin as an artificial O2 carrier.
abstract: Covalent core-shell structured protein clusters of hemoglobin (Hb) and human serum albumin (HSA) (HbX-HSAm) (m = 2, 3) with novel physiological properties were generated by linkage of Hb surface lysins to HSA cysteine-34 via an α-succinimidyl-ε-maleimide cross-linker (X: 1 or 2). The isoelectric points of HbX-HSAm (pI = 5.0-5.2) were markedly lower than that of Hb and almost identical to that of HSA. AFM and TEM measurements revealed a triangular Hb1-HSA3 cluster in aqueous medium. The complete 3D structure of Hb1-HSA3 based on TEM data was reconstructed, revealing two possible conformer variants. All HbX-HSAm clusters showed a moderately higher O2 affinity than the native Hb. Furthermore, the exterior HSA units possess a remarkable ability to bind lumiflavin (LF). The addition of NADH to an aqueous solution of the met-Hb2-(HSA-LF)3 cluster reduced the inactive ferric Hb center to the functional ferrous Hb. This O2-carrying hemoprotein cluster with strongly negative surface net charge, high O2 affinity, and NADH-dependent reductase unit can support a new generation of molecular architecture for red blood cell substitutes.
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University , 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan.
authors.forename: Daiki
authors.initials: D
authors.lastname: Tomita
authors.forename: Takuya
authors.initials: T
authors.lastname: Kimura
authors.forename: Hitomi
authors.initials: H
authors.lastname: Hosaka
authors.forename: Yuta
authors.initials: Y
authors.lastname: Daijima
authors.forename: Risa
authors.initials: R
authors.lastname: Haruki
authors.forename: Kai
authors.initials: K
authors.lastname: Ludwig
authors.forename: Christoph
authors.initials: C
authors.lastname: Böttcher
authors.forename: Teruyuki
authors.initials: T
authors.lastname: Komatsu
mesh_terms: D002942:Circular Dichroism; D006454:Hemoglobins / Q000737:chemistry*; D006801:Humans; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D010100:Oxygen / Q000737:chemistry*; D011487:Protein Conformation; D012709:Serum Albumin / Q000737:chemistry*
chemical_list: D006454:Hemoglobins; D012709:Serum Albumin; D010100:Oxygen