The whey acidic protein family: A new signature motif and three-dimensional structure by comparative modeling

Whey acidic proteins (WAP) from the mouse, rat, rabbit, camel, and pig comprise two "fonr-disnlfide core" domains. From a detailed analysis of all sequences containing this domain, we propose a new PROSITE motif ([KRHGVLN]X-{PFj-X-[CF]-[PQSVLI]-X(9,19)-C-(P}-X-[DN]-X-/N}[CE]-X(5)-C-C) to accurately identify new fonr-disitlflde core proteins. A consensus model for the WAP proteins is proposed, based on the human mucous proteinase inhibitor crystal structure. This article presents a detailed atomic model for the two-domain porcine WAP sequence by comparative modeling. Surface electrostatic potential calculations indicate that the second domain of the pig WAP model is similar to the functional human mucous proteinase inhibitor domains, whereas the first domain may be nonfunctional. ©2000 by Elsevier Science Inc.