Dibromohexane

Chemicals used for monomer and polymer synthesis included sodium hydroxide, hydrobenzoic acid, dibromohexane, 1-methyl-2-pyrrolidinone, SA monomer, and triethylene glycol purchased from Sigma Aldrich (St. Louis, MO, USA). Acetic anhydride, ethyl ether, petroleum ether, chloroform, methylene chloride, hexane, acetone, sulfuric acid, potassium carbonate, dimethyl formamide, toluene, acetonitrile, N,N-dimethylacetamide, and acetic acid were purchased from Fisher Scientific (Fairlawn, NJ, USA); 4-p-fluorobenzonitrile was purchased from Apollo Scientific (Cheshire, UK). For ¹H NMR analysis of the copolymers, deuterated chloroform and dimethyl sulfoxide were purchased from Cambridge Isotope Laboratories (Andover, MA, USA). The N-terminal region of a recombinant PspA (UAB055, PspA/Rx1 AA1 to 303, clade 2 PspA of the PspA family 1) was produced by Dr. David McPherson (University of Alabama at Birmingham) as described previously (55 (link)). Prior to immunization, endotoxin was removed from the protein using endotoxin removal beads (Miltenyi Biotec, Bergisch Gladbach, Germany) according to the manufacturer’s instructions followed by dialysis and lyophilization. The final endotoxin content of the protein was determined to be less than 1.9 EU/mg as determined by a limulus amebocyte lysate chromogenic endotoxin quantification kit (Thermo Fisher Scientific).