Abstract
The polypeptide composition of a Photosystem II (PS II) core complex from higher plant chloroplasts has been characterized by subjecting the isolated complex to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Two polypeptides in the 40-50 kDa size class, attributed to the chlorophyll a-binding apoproteins of PS II, were resolved when the urea concentration in the SDS-polyacrylamide gel electrophoresis was greater than 1 M. The two chlorophyll a-binding proteins were dissimilar in their primary structure based upon their different hydrolysis products on SDS-polyacrylamide gel electrophoresis following papain treatment. The core complex contained three additional polypeptides. Two polypeptides in the 30-34 kDa size class were resolved when the urea concentration in the gel system was increased to greater than 4 M. One of the polypeptides in this size class was identified as the herbicide-binding protein from azido[14C]atrazine labeling studies. The herbicide-binding protein displayed an anomalous electrophoretic migration behavior in SDS-polyacrylamide gel electrophoresis in the presence or absence of urea; its apparent molecular weight decreased when the urea concentration increased. The fifth protein component of the core complex was attributed to cytochrome b-559 which was found to consist of the ascorbate- and dithionite-reducible forms in the samples prior to SDS solubilization.
Original language | English (US) |
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Pages (from-to) | 142-150 |
Number of pages | 9 |
Journal | BBA - Bioenergetics |
Volume | 724 |
Issue number | 1 |
DOIs | |
State | Published - Jul 29 1983 |
Keywords
- Atrazine
- Chlorophyll fluorescence
- Herbicide-binding protein
- Photosystem II
- Polypeptide composition
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Cell Biology