Membrane-Bound Peaks

Functional photosystems I and II were isolated from labeled pea chlo-roplasts by the digitonin method of Boardman, and were run on 15% gels. The distribution of protein bands, total chlorophyll, chlorophylls a and b, and the radioactivity in peak D were determined (Table II). The ratios of chlorophyll a to chlorophyll b show that the enrichment of the photosystems is as expected. Each photosystem is enriched in certain of the stained protein bands, but peak D is not enriched in either photosystem. 

Fraction Ratio Chlorophyll (%) chlorophyll a/b Enriched protein bands Radioactivity in peak D (%) 

Instead, the bulk of peak D is rendered soluble by digitonin. The fact that band 14 is enriched in the 10 kg fraction, while peak D is not, suggests that the two are not identical. 

The remainder of this chapter discusses our work on four questions about chloroplast protein synthesis  

Lincomycin is very effective at inhibiting chloroplast ribosomal function, but not cytoplasmic ribosomal function, when fed to excised greening shoots of Pisum sativum Maximal effects are observed when the 

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A cytochrome having the a peak at 579 nm is obtained from Leptospirillum ferrooxidans DSM 2706 (Hart et al., 1991). The cytochrome has 1 atom of zinc in addition to heme iron. Its molecular mass is 17.9 kDa and its Emj5 is +0.68 V (Blake et al., 1993). From L. ferrooxidans P3A, a cytochrome with the molecular mass of 12 kDa is obtained, while the 17.9 kDa cytochrome is not obtained. In any case, nothing is known about the function of the L. ferrooxidans cytochromes. Moreover, Metallosphaera sedula and Acidianus brierleyi have a membrane-bound yellow cytochrome which is reduced by ferrous ion (Blake and McGinness, 1993 Blake et al., 1993). However, the description here about cytochromes c will be limited to the proteins that have been purified from A. ferrooxidans and well characterized. 

Fig. 1. Isolation of cholinergic vesicles from Torpedo nobiliana by zonal centrifugation in a sucrose-NaCl gradient. The large protein peak corresponds to soluble protein, the small one to membrane bound protein. A few particles corresponding to nerve ending particles may have been formed, as...

When the point is placed, the Show Time Plot button will become active. Click on it, and a time plot of C will appear. Also plot the time profile for PI3KA. We can confirm that, while the cell s receptor occupancy displays a step like time profile, the cell s membrane-bound PI3K (PI3KA) levels display a transient peak before settling back to its prestimulus level (Fig. 6e). 

In contrast to RCs from R. viridis where charge separation is blocked by double reduction of and Q, the membrane bound RC of the Dll mutant could be cast into a PVA film, thus allowing the application of electric fields at low temperatures. Measurements of the steady state fluorescence yield show that the lifetime of P increases by 1.5% in an external electric field of c 710 V/cm. This effect is by a factor of 2 4 larger than the Stark effect measured in the peak of the Qy absorption band of the dimer P. In principle, this field induced decrease of the fluorescence may arise from two sources (i) the increase of the internal conversion rate by mixing in charge transfer states and (ii) a field induced transfer to the inactive B-branch. 

The membrane-bound lysosomal enzyme in rat brain has been solubilized from the particulate fraction and partially purified (Miyagi et aL, 1990a). The sialidase activity can be separated into two peaks, corresponding to sialidases I and II, by AH-Sepharose column chromatography. Using specific antibodies against the enzymes, it has been shown that sialidase I is localized in synaptosomal membranes, and sialidase II in both synaptosomal and lysosomal membranes. The latter species has been further purified by 2150-fold with a recovery of 0.7%. 

Cyclic voltammetry was performed with the ADH-NAD-MB/polypyrrole electrode in 0 1 M phosphate buffer (pH 8.5) at a scan rate of 5 mV s . The cyclic voltammo-gram is presented in Fig.5. A pai F or redox peaks was attributed to the oxidation and reduction ones of MB. The substrate ethanol of ADH caused the anodic current at +0.10 V vs. Ag/AgCl to increase. These results suggest a possible electron transfer from membrane-bound ADH to the electrode through membrane-bound NAD and MB with the help of the conductive polymer of polypyrrole. 

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