Better Peptides via Chemical Glycosylation: Somatostatin Analogues Having a Human Complex-Type N-Glycan with Improved Drug Properties.

Somatostatin (somatotropin release-inhibiting factor, SRIF) is a growth hormone inhibitory factor in the form of a 14- or 28-amino acid peptide. SRIF affects several physiological functions through its action on five distinct SRIF receptor subtypes (sst1-5). Native SRIF has only limited clinical applications due to its rapid degradation in plasma.

Chemical synthesis of homogeneous human glycosyl-interferon-β that exhibits potent antitumor activity in vivo.

Chemical synthesis of homogeneous human glycoproteins exhibiting bioactivity in vivo has been a challenging task. In an effort to overcome this long-standing problem, we selected interferon-β and examined its synthesis. The 166 residue polypeptide chain of interferon-β was prepared by covalent condensation of two synthetic peptide segments and a glycosylated synthetic peptide bearing a complex-type glycan of biological origin.

Regulation of T cell response by blocking the ICOS signal with the B7RP-1-specific small antibody fragment isolated from human antibody phage library.

A costimulatory signal is required for the full activation of T cells, in addition to the antigen-specific signal via the T cell receptor. The inducible costimulator, ICOS is one of the costimulatory molecules that play an essential role in this process, particularly in the expansion or the development of effector T cells. As blocking of the interaction between ICOS and its ligand, B7RP-1, suppresses the T cell response, it can be applied to the treatment of allograft rejection or autoimmune diseases.