Kallikreins protein models

The crystal structure has been revealed for some rodent kallikreins. The three-dimensional structure of a horse orthologue of the human hK3 has also been reported [28]. In contrast, hKl and hK6 are the only human kallikreins for which crystal structures have been determined [48-50]. Most of the discussion in this section is derived from comparative model building of the human kallikrein proteins. 

Kallikreins can be roughly divided into two categories, the classical kallikreins (hKl, hK2, and hK3) and the new kallikreins. The new kallikreins appear to be unique in their three-dimensional structure and share some features with trypsins and other features with the classical kallikreins. Comparative protein models show that the pattern of hydrophobic side-chain packing in the protein core is nearly identical in all human kallikreins, and the observed differences occur within the solvent-exposed loop segments. 

J. Rapp, B. Dowell, T. Lovgren, K. Pettersson, H. Lilja. Determination and analysis of antigenic epitopes of prostate specific antigen (PSA) and human glandular kallikrein 2 (hK2) using synthetic peptides and computer modeling. Protein Sci. 1998, 7, 259-269. 

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