Proteolysis in Euglena gracilis. III. Cysteine, but not Serine roteinases are Involved in Chloroplast Formation in Resting Cells1)

Krauspe, R.; Scheer, Angellka

doi:10.1016/s0176-1617(86)80228-0

Cited by 3 publications

(1 citation statement)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The barley and pea (29) enzymes are both insensitive to leupeptin, in contrast to the algal protease (19). However, it is still undetermined whether leupeptin inhibits specifically serinetype or cysteine-type proteinases (23,24). The lack of inhibition of the pPorA-degrading protease by leupeptin, phenylmethylsulfonyl fluoride, and diisopropyl fluorophosphate, which are serine-type proteinase inhibitors (6,11), and the strong coincidence between the inhibitory effects of antipain and E-64 appear to favor the explanation that the barley enzyme is a cysteine-type proteinase.…”

Section: Discussionmentioning

confidence: 99%

A Light-Induced Protease from Barley Plastids Degrades NADPH:Protochlorophyllide Oxidoreductase Complexed with Chlorophyllide

Reinbothe

Apel

Reinbothe

1995

Molecular and Cellular Biology

View full text Add to dashboard Cite

The NADPH:protochlorophyllide oxidoreductase precursor protein (pPorA) of barley (Hordeum vulgare L. cv. Carina), synthesized from a full-length cDNA clone by coupling in vitro transcription and translation, is a catalytically active protein. It converts protochlorophyllide to chlorophyllide in a light-and NADPH-dependent manner. At least the pigment product of catalysis remains tightly bound to the precursor protein. The chlorophyllide-pPorA complex differs markedly from the protochlorophyllide-pPorA complex with respect to sensitivity to attack by a light-induced, nucleus-encoded, and energy-dependent protease activity of barley plastids. The pPorA-chlorophyllide complex is rapidly degraded, in contrast to pPorA-protochlorophyllide complexes containing or lacking NADPH, which are both resistant to protease treatment. Unexpectedly, pPorA devoid of its substrates or products was less sensitive to proteolysis than the pPorA-chlorophyllide complex, suggesting that both substrate binding and product formation during catalysis had caused differential changes in protein conformation.

show abstract