Abstract: The inventors discovered that viscosity of a protein solution can be estimated by measuring the apparent particle size or apparent molecular weight by a small angle X-ray scattering (SAXS) method or X-ray solution scattering method, which enables measurement of small amounts of samples, and then correlating those measurement results with viscosity of the protein solution.

Abstract: The inventors discovered that viscosity of a protein solution can be estimated by measuring the apparent particle size or apparent molecular weight by a small angle X-ray scattering (SAXS) method or X-ray solution scattering method, which enables measurement of small amounts of samples, and then correlating those measurement results with viscosity of the protein solution.

Abstract: The present inventors have found that when screening for cyclic peptide compounds that can specifically bind to a target molecule, the use of a library including cyclic peptide compounds having a long side chain in the cyclic portion can improve the hit rate for cyclic peptide compounds that can specifically bind to the target molecule. Meanwhile, the present inventors have found that tryptophan and tyrosine residues, which have conventionally been used in oral low molecular-weight pharmaceuticals and are amino acid residues having an indole skeleton or a hydroxyphenyl group, are not suitable for peptides intended to attain high membrane permeability.

Abstract: The inventors discovered that viscosity of a protein solution can be estimated by measuring the apparent particle size or apparent molecular weight by a small angle X-ray scattering (SAXS) method or X-ray solution scattering method, which enables measurement of small amounts of samples, and then correlating those measurement results with viscosity of the protein solution.