Abstract: The present invention relates to a conjugate in which a polypeptide capable of forming a dimer is fused to the C-terminus of the heavy chain or light chain of an antibody or fragment thereof, a composition for increasing antigen-binding avidity of an antibody in proportion to the density of a target antigen, and a method for increasing antigen-binding avidity using the same. The present invention also relates to the treatment or diagnosis of diseases using the conjugate.

Abstract: The present invention relates to a thermostable enzyme with a 2.1 Å crystal structure of a propeller type comprising six external blades that encompass the outer boundary of the crystal and six internal calcium-binding sites that are embedded inside the above crystal. Each of the six blades comprises 4 or 5 anti-parallel &bgr;-strands, and the six calcium binding sites consist of 3 high-affinity calcium binding sites and 3 low-affinity binding sites, which are involved in the enzyme's thermostability and catalytic activity, respectively. The above-mentioned Ca2+ binding motifs are expected to be utilized in synthesizing highly thermostable proteins and the elucidation of active sites of an enzyme from a three-dimensional structure can help to design new enzymes having those sites with the aid of recent advanced technology of protein engineering.

Abstract: The present invention relates to a method for preparing the crystal of human derived TRAIL protein and TRAIL receptor protein sDR5 complex and the crystal of TRAIL-sDR5 complex prepared by the method. The present invention also TRAIL relates to a three-dimensional structure of TRAIL protein in the form of complex with TRAIL receptor sDR5 as well as TRAIL protein itself, and specific residues existed in the contact central region of AA″ loop. The three-dimensional structure of TRAIL-sDR5 complex and the specific residues in the AA″ loop of the present invention can be effectively used for not only the development of TRAIL protein having the better cytotoxic activity and having the improved receptor biding affinity, which specifically kills viral infected cells or cancer cells but also molecular strategy for regulating the binding specificity between TNF and TNFR family.

Abstract: The present invention relates to a thermostable enzyme with a 2.1 Å crystal structure of a propeller type comprising six external blades that encompass the outer boundary of the crystal and six internal calcium-binding sites that are embedded inside the above crystal. Each of the six blades comprises 4 or 5 anti-parallel &bgr;-strands, and the six calcium binding sites consist of 3 high-affinity calcium binding sites and 3 low-affinity binding sites, which are involved in the enzyme's thermostability and catalytic activity, respectively. The above-mentioned Ca2+ binding motifs are expected to be utilized in synthesizing highly thermostable proteins and the elucidation of active sites of an enzyme from a three-dimensional structure can help to design new enzymes having those sites with the aid of recent advanced technology of protein engineering.