Resolution of thylakoid polyphenol oxidase and a protein kinase
The predominant protein kinase activity in octylglucoside (OG) extracts of spinach thylakoids has been attributed to a 64-kDa protein, tp64. Recent work calls into question the relation between tp64 and protein kinase activity, which were fractionated apart using fluid phase IEF and hydroxylapatite chromatography. Hind et al. sequenced tp64 from the cDNA and showed it to be a polyphenol oxidase (PPO) homolog. Its transit peptide indicates a location for the mature protein within the thylakoid lumen, where there is presumably no ATP and where it is remote from the presumed kinase substrates: the stromally exposed regions of integral PS-II membrane proteins. Here the authors suggest that the kinase is a 64-kDa protein distinct from tp64.
- Research Organization:
- Brookhaven National Lab., Upton, NY (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 192405
- Report Number(s):
- BNL--62487; CONF-9508202--3; ON: DE96003576
- Country of Publication:
- United States
- Language:
- English
Similar Records
Purification and characterization of a thylakoid protein kinase
Spinach thylakoid polyphenol oxidase isolation, activation, and properties of the native chloroplast enzyme