Invertebrate aspartyl/asparaginyl beta-hydroxylase: potential modification of endogenous epidermal growth factor-like modules
Monkovic, D.D.; VanDusen, W.J.; Petroski, C.J.; Garsky, V.M.; Sardana, M.K.; Zavodszky, P.; Stern, A.M.; Friedman, P.A.
Biochemical and Biophysical Research Communications 189(1): 233-241
1992
ISSN/ISBN: 0006-291X PMID: 1449478 Document Number: 399619
An invertebrate alpha-ketoglutarate-dependent aspartyl/asparaginyl beta-hydroxylase, which posttranslationally hydroxylates specific aspartyl or asparaginyl residues within epidermal growth factor-like modules, was identified, partially purified and characterized. Preparations derived from two insect cell lines catalyzed the hydroxylation of the expected asparaginyl residue within a synthetic epidermal growth factor-like module. This activity was found to be similar to that of the purified mammalian aspartyl/asparaginyl beta-hydroxylase with respect to cofactor requirements, stereochemistry and substrate sequence specificity. Furthermore, recombinant human C1 hivin r, expressed in an insect cell-derived baculovirus expression system, was also found to be hydroxylated at the expected asparaginyl residue. Thus, these results establish the potential for invertebrate aspartyl/asparaginyl hydroxylation. Since several invertebrate proteins known to be required for proper embryonic development contain a putative consensus sequence that may be required for hydroxylation, the studies presented here provide the basis for further investigations concerned with identifying hydroxylated invertebrate proteins and determining their physiologic function.