Patent ID: 7648962

Claim:
A natriuretic compound conjugate comprising: (a) a biologically active natriuretic compound wherein the natriuretic compound comprises a brain natriuretic peptide (BNP) or a biologically active peptide segment of BNP that exhibits NPR-A receptor binding activity, and comprises: (i) a disulfide loop for binding to the NPR-A receptor; and (ii) at least one modifying moiety conjugation site; and (b) at least one modifying moiety attached to said modifying moiety conjugation site, wherein the modifying moiety conjugation site comprises a Lysine amino acid residue of BNP, wherein the modifying moiety comprises a polyalkylene glycol moiety “PAGn” moiety wherein the PAG moiety is a polyethylene glycol moiety and n is 1 to 8, and at least one of the following groups; a linking group “X” attached to the PAG moiety; an internal alkyl group “(—CH 2 —)o” wherein o is 4 to 10; wherein the modifying moiety is a formula: wherein PAG is described above X′ is —O— or —N—; and each o is described above wherein said natriuretic compound conjugate exhibits one or more advantages selected from the group consisting of increased resistance to enzymatic degradation relative to a corresponding unconjugated natriuretic compound, increased circulating half life, increased bioavailability, and prolonged duration of effect.