Hemoglobin−Superoxide DismutaseChemical Linkages That Create a Dual-Function Protein

Abstract

Chemical reagents were designed to cross-link and connect hemoglobin and superoxide dismutase, combining the oxygen transport and superoxide-removal capabilities of the red cell in a dual-function protein. Reaction of 1 with thiol-protected hemoglobin followed by reduction produces cross-linked hemoglobin with a free thiol on the cross-link. Reaction of SOD with 5 produces a cross-linked protein with a maleimide on the cross-link. Addition of the hemoglobin-thiol to the SOD-maleimide produces a protein with the desired dual properties. Hemoglobin's oxygenation cooperativity is lowered as a result of being in the conjugate, while SOD's activity is equal to that of the native protein.

Core–shell clusters of human haemoglobin A and human serum albumin: artificial O2-carriers having various O2-affinities

“…Over the last 30 years, haemoglobin (Hb)-based O 2 carriers (HBOCs) of several kinds have been prepared and evaluated as red blood cell (RBC) substitutes, [1][2][3][4] such as polymerized Hb, [5][6][7] poly(ethyleneglycol)-conjugated Hb, [8][9][10] enzyme-linked Hb, 11,12 and saccharide-bound Hb. 13 Nevertheless, because of several concerns, none has been assigned yet for practical use.…”

The synthesis of a carbon‐14 labeled pegylated Adnectin™ for placental transfer studies in guinea pigs

“…To assess placental permeability to adnectins in pregnant guinea pigs, a radiolabeled adnectin, ATI-1072, bound to polyethylene glycol through a [ 14 C] Maleimide linker, was synthesized from [1,4-14 C]Maleic acid as described later. [1][2][3] …”

Bioorthogonal phase-directed copper-catalyzed azide–alkyne cycloaddition (PDCuAAC) coupling of selectively cross-linked superoxide dismutase dimers produces a fully active bis-dimer

“…5, 6 Saifer and coworkers showed that modification of SOD with 35 kDa PEG extends the half-life of SOD in circulation from less than 10 minutes to over 24 h. 7 However, the resulting modified protein consists of mixtures that are difficult to characterize and that may elicit an inflammatory response. [10][11][12][13] Our approach involves chemical introduction of specific functional sites for phase-directed copper-catalyzed azidealkyne cycloaddition (PDCuAAC) to effect site-directed proteinprotein coupling. [10][11][12][13] Our approach involves chemical introduction of specific functional sites for phase-directed copper-catalyzed azidealkyne cycloaddition (PDCuAAC) to effect site-directed proteinprotein coupling.…”

“…[10][11][12][13] Our approach involves chemical introduction of specific functional sites for phase-directed copper-catalyzed azidealkyne cycloaddition (PDCuAAC) to effect site-directed proteinprotein coupling. [10][11][12][13] The resulting species has the exact mass expected for a coupled 64 kDa entity, which exceeds the threshold size that is needed for a protein to remain in circulation without interference from renal filtration (30-50 kDa). Once the initial CuAAC reaction occurs, the remaining alkyne is brought into the aqueous phase by the attachment of the other end to the protein.…”