Abstract: Tangential flow filtration (TFF) is a size-based separation method conventionally used for buffer exchange, concentration, pathogen removal, and for coarse purification. Disclosed herein, TFF was used for selective purification of proteins in their complexed form. In some examples, this process was demonstrated to recover human serum albumin (HSA) in its complexed form from an artificially produced mixture of hemoglobin (Hb) and HSA and from plasma using an anti-HSA polyclonal immunoglobulin G (IgG) as the target-protein binding molecule (TPBM). Moreover, another embodiment of the method recovered haptoglobin (Hp) in its complexed form from human Cohn Fraction IV using Hb as the TPBM. In addition, a mathematical model used to describe the TFF purification process provided that product recovery could be increased without loss of purity by introducing TFF filters with the same MWCO in series.

Abstract: The present disclosure provides methods of treating plasma protein imbalances or depletion (e.g., plasma protein imbalances or depletion caused by hemorrhagic shock or other clinical conditions), in particular by administering protein compositions derived from plasma or plasma isolates.

Abstract: Provided herein are apohemoglobin-haptoglobin complexes as well as apohemoglobin-haptoglobin complexes comprising an active agent coordinated thereto. Methods of using these compositions are also described.

Abstract: Provided herein are methods for purifying proteins from mixtures of proteins using ultrafiltration, such as tangential-flow filtration (TFF). Provided herein are methods for isolating an apoprotein from a protein solution comprising a conjugated protein, wherein the conjugated protein comprises the apoprotein and a hydrophobic ligand associated with the apoprotein.