Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.64 (proteinase K)
4,071 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In transmissible spongiform encephalopathies (TSE), the endogenous protease-sensitive prion protein (PrP-sen) of the host is converted to a pathologic form (PrP-res) that has greatly enhanced proteinase K resistance, insolubility, and beta sheet content. To investigate the possibility that alterations at aspartyl or asparaginyl residues in the form of D-aspartate and/or L-isoaspartate could play a role in either the formation or stabilization of PrP-res in TSE-infected animals, we assayed for the presence of these abnormal residues in PrP-res. Protein D-aspartyl/L-isoaspartyl carboxyl methyltransferase (PIMT) was used to methylate and radiolabel altered aspartyl residues, which were detected in PrP-res, but at low levels (0.5 mole%). The scarcity of D-aspartyl and/or L-isoaspartyl groups in PrP-res suggests that this modification is unlikely to be primarily responsible for the differences between PrP-res and PrP-sen. However, it remains possible that such modifications in substoichiometric numbers of PrP molecules could help to initiate the PrP-res formation or stabilize PrP-res polymers in vivo.
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PMID:Measurement of altered aspartyl residues in the scrapie associated form of prion protein. 961 58