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  • 1
    Electronic Resource
    Electronic Resource
    Variation in the polypeptide composition of phycobilisomes from Anacystis nidulans and three pigment mutants (1986)
    Springer
    Photosynthesis research 8 (1986), S. 149-159 
    Details
    ISSN: 1573-5079
    Keywords: allophycocyanin ; Anacystis ; phycobilisomes ; phycocyanin ; pigment mutants polypeptides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phycobilisomes, light harvesting antenna pigment systems, were studied from Anacystis nidulans wild type and from several spontaneous pigment mutants selected for improved growth in far-red light (〉650 nm). This is the first characterization and description of polypeptide composition of phycobilisomes from spontaneous mutants (not chemically induced) of A. nidulans. The mutants had significant changes in the phycobiliprotein content relative to chlorophyll (Chl). Two phycobiliproteins, C-phycocyanin (λmax 625 nm) and allophycocyanin (λmax 650 nm) were present in a molar ratio of ∼3:1 in the wild type. In the mutants the amount of allophycocyanin (APC) per cell remained constant but the phycocyanin (PC) content varied. Phycobilisomes of the mutants 85Y, 19Y and 59G contained PC and APC in a molar ratio of 0.4:1, 0.7:1, and 1:1, respectively. Even though the phycobilisomes of mutant 85Y showed the greatest reduction in PC and consisted mostly of the APC core, the phycobilisomes were still functional and the growth rate of the 85Y cells was similar to the wild type. Fluorescence emission maxima of wild type and all the mutants were at 680 nm (23°C). Excitation maxima corresponded closely with expectations from absorption spectra. On SDS-PAGE gradient gels wild-type phycobilisomes had the usual 17–19 kD polypeptides of PC and APC, plus polypeptides at ca. 78, 56, 39, 36 and 31 kD. Mutants 19Y and 85Y, with the greatest PC deficiency were also deficient in the 36 and 39 kD polypeptides, presumably due to a decrease in peripheral rod structures. Energetically functional hybrid phycobilisomes were obtained when complexes of phycoerythrin-phycocyanin from Nostoc were mixed with dissociated phycobilisomes of wild-type and mutant 85Y. The 31 kD polypeptide is common to both species and immunologically cross reactive.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00035245
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Photosynthetic and respiratory electron transport in a cyanobacterium (1986)
    Springer
    Photosynthesis research 9 (1986), S. 135-147 
    Details
    ISSN: 1573-5079
    Keywords: blue-green algae ; eyanobacterium ; cytochrome C553 ; electron transport ; photosynthesis ; respiration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the cyanobacterium Agmenellum quadruplicatum steady-state redox conditions were monitored in vivo for cytochrome (δ+c553) and P700 versus intensities of an actinic light 1 or light 2 (mainly absorbed by photosystems, and 2, respectively). Parallel measurements of O2 evolution were used to calibrate intensities for rates of electron transfer. Results show that the quality of actinic light (as light 1 or light 2) depends on intensity as well as wavelength. The contribution of electron flow from respiration is confirmed by observations of relative rate of photoreaction 1 estimated from Ip (intensity × fraction of P700 reduced). With 3,- (3,4-dichlorophenyl-1, 1-dimethylurea) (DCMU) the rate of photoreaction 1 depends upon, and is sensitive to small changes in, the rate of dark respiration. Very slow transient dark reductions of Cyt (f+c553) and P700 following any low intensity actinic light 1 are attributed to respiratory electron flow. Cyclic electron flow around photoreaction 1 cannot be large compared to dark respiration and cannot vary significantly with light intensity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00029739
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  • 3
    Electronic Resource
    Electronic Resource
    Is there significant cyclic electron flow around photoreaction 1 in cyanobacteria? (1987)
    Springer
    Photosynthesis research 14 (1987), S. 55-69 
    Details
    ISSN: 1573-5079
    Keywords: blue-green algae ; cyanobacteria ; cyclic electron flow ; photoreaction 1 ; photosynthesis ; P700 ; respiration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Evidence for a cyclic electron flow has been sought by study of the steady-state poise of P700 and rate of photoreaction 1 in three cyanobacteria. Under an actinic light 1 (440 or 680 nm) the rate of photoreaction 1 is limited by the rate of electron supply provided by photoreaction 2 and by all return electron flow from low potential donors such as ferredoxin and NAD(P)H. Plots of p, the steady-state fraction of P700 reduced, versus the reciprocal intensity, 1/I, yield linear segments of slope Ip. From considerations of a simple model the slopes and extrapolated intercepts of the linear segments provide estimates of the rate of return electron flow. Analysis shows that the total return electron flow cannot be large, by one estimate not more than three times the rate of dark respiration. This result leads to a conclusion that cyclic electron flow (and any dependent phosphorylation) is not a significant process in these cyanobacteria at ordinary light intensities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00019592
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  • 4
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    Unknown
    Spacecraft design project: High latitude communications satellite (1989)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The spacecraft design project was part of AE-4871, Advanced Spacecraft Design. The project was intended to provide experience in the design of all major components of a satellite. Each member of the class was given primary responsibility for a subsystem or design support function. Support was requested from the Naval Research Laboratory to augment the Naval Postgraduate School faculty. Analysis and design of each subsystem was done to the extent possible within the constraints of an eleven week quarter and the design facilities (hardware and software) available. The project team chose to evaluate the design of a high latitude communications satellite as representative of the design issues and tradeoffs necessary for a wide range of satellites. The High-Latitude Communications Satellite (HILACS) will provide a continuous UHF communications link between stations located north of the region covered by geosynchronous communications satellites, i.e., the area above approximately 60 N latitude. HILACS will also provide a communications link to stations below 60 N via a relay Net Control Station (NCS), which is located with access to both the HILACS and geosynchronous communications satellites. The communications payload will operate only for that portion of the orbit necessary to provide specified coverage.
    Keywords: SPACECRAFT DESIGN, TESTING AND PERFORMANCE
    Type: NASA-CR-186689 , NAS 1.26:186689
    Format: application/pdf
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    NASA TECHNICAL REPORTS
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