Development of a novel human adrenomedullin derivative: human serum albumin-conjugated adrenomedullin

Abstract

Adrenomedullin is a biologically active peptide with multiple functions. Here, we have developed a novel human serum albumin-adrenomedullin (HSA-AM) conjugate, which was synthesized by the covalent attachment of a maleimide derivative of adrenomedullin to the 34th cysteine residue of human serum albumin via a linker. Denaturing gel electrophoresis and Western blotting for HSA-AM yielded a single band with adrenomedullin immunoreactivity at the position corresponding to a molecular weight (MW) of 73 kDa. Following gel-filtration chromatography, the purified HSA-AM showed a single main peak corresponding with a MW of 73 kDa, indicating that HSA-AM is a monomer. Both adrenomedullin and HSA-AM stimulated the intracellular accumulation of cyclic AMP in HEK-293 cells stably expressing the adrenomedullin 1 receptor. The pEC50 values for adrenomedullin and HSA-AM were 8.660 and 7.208 (equivalent to 2.19 nM and 61.9 nM as EC50), respectively. The bioavailability of HSA-AM compared with that of adrenomedullin was much improved after subcutaneous administration in the rat, which was probably due to the superior resistance of HSA-AM toward endogenous proteases and its reduced clearance from the blood. HSA-AM may be a promising drug candidate for clinical application.

Adrenomedullin: A Novel Therapeutic for the Treatment of Inflammatory Bowel Disease

“…Soon, we plan to initiate a phase I study using 60 kDa PEGylated AM. In addition, we have successfully developed IgG Fc region fusion AM [51], and human albumin-modified AM [52] and are currently conducting preclinical studies using these modified AMs. iomedicines 2021, 9, x FOR PEER REVIEW 8…”

Development of Long-Acting Human Adrenomedullin Fc-Fusion Proteins

“…To improve the pharmacokinetic properties, we developed polyethylene glycol (PEG) -conjugated AM (PEG-AM) [ 7 ] and human serum albumin-conjugated AM [ 8 ]. The amino-terminal region of AM does not contribute to the biological activity of AM and we previously conjugated large molecules, such as PEG and human serum albumin, to the N-terminal of AM.…”