Molecular basis of the heat denaturation of photosystem II

Biochemistry ◽  
1989 ◽  
Vol 28 (16) ◽  
pp. 6686-6695 ◽  
Author(s):  
Lynmarie K. Thompson ◽  
Richard Blaylock ◽  
Julian M. Sturtevant ◽  
Gary W. Brudvig
Keyword(s):  
Photosystem Ii ◽  
Molecular Basis ◽  
Heat Denaturation

scholarly journals The emergence of a atrazine resistant black nightshade (Solanum nigrum L.) biotype and molecular basis of the resistance

2010 ◽  
Vol 40 (No. 3) ◽  
pp. 94-100 ◽  
Author(s):  
J. Salava ◽  
D. Chodová ◽  
K. Nováková
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosystem Ii ◽  
Rapid Detection ◽  
Molecular Basis ◽  
Restriction Analysis ◽  
D1 Protein ◽  
Solanum Nigrum ◽  
Gene Encoding ◽  
Black Nightshade ◽  
Pcr Products

Seeds from atrazine resistant plants of black nightshade (<I>Solanum nigrum </I>L.)<I> </I>were collected at the railway station Prague-Vršovice, seeds from susceptible plants in Vyšehořovice (Prague East district). Tests on emergence showed that in both resistant and susceptible biotypes it was highest at a seeding depth of 1 mm, and that at the same seeding depth there were statistically significant differences in emergence between the resistant and susceptible biotypes. The resistance or susceptibility to atrazine was tested by both a chlorophyll fluorescence assay and spraying with atrazine. A region of the gene encoding D1 protein of photosystem II was sequenced and compared between the resistant and susceptible biotypes. Resistance to atrazine in the <I>S. nigrum</I> biotype from Vršovice was conferred by a glycine for serine substitution at residue 264 of the D1 protein. In the plants of the biotypes there was excellent correspondence between the presence of the mutation and herbicide resistance. The assay based on restriction analysis of PCR products can be used for rapid detection of the mutation in populations of black nightshade.

Renilla Bioluminescence: A Morphologic Approach to the Location of Photocytes

1974 ◽  
Vol 32 ◽  
pp. 208-209
Author(s):  
Ben O. Spurlock ◽  
Milton J. Cormier
Keyword(s):  
Excited State ◽  
Ground State ◽  
Molecular Basis ◽  
Light Emission ◽  
Chemical Basis ◽  
Electronic Excited State ◽  
Colonial Form ◽  
The Common ◽  
Eighteenth And Nineteenth Centuries ◽  
Catalyzed Oxidation

The phenomenon of bioluminescence has fascinated layman and scientist alike for many centuries. During the eighteenth and nineteenth centuries a number of observations were reported on the physiology of bioluminescence in Renilla, the common sea pansy. More recently biochemists have directed their attention to the molecular basis of luminosity in this colonial form. These studies have centered primarily on defining the chemical basis for bioluminescence and its control. It is now established that bioluminescence in Renilla arises due to the luciferase-catalyzed oxidation of luciferin. This results in the creation of a product (oxyluciferin) in an electronic excited state. The transition of oxyluciferin from its excited state to the ground state leads to light emission.

Characterization of photosystem II with the atomic-force microscope

1992 ◽  
Vol 50 (2) ◽  
pp. 1146-1147
Author(s):  
Kathleen M. Marr ◽  
Mary K. Lyon
Keyword(s):  
Photosystem Ii ◽  
Atomic Force Microscope ◽  
Three Dimensional ◽  
Biologically Active ◽  
Atomic Force ◽  
Freeze Etching ◽  
Image Averaging ◽  
Oxygen Evolving ◽  
Averaging Techniques

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.

Androgen-induced plasticity at a “vocal” neuromuscular synapse

1994 ◽  
Vol 52 ◽  
pp. 32-33
Author(s):  
Darcy B. Kelley ◽  
Martha L. Tobias ◽  
Mark Ellisman
Keyword(s):  
Xenopus Laevis ◽  
Motor Neurons ◽  
Sexual Differentiation ◽  
Molecular Basis ◽  
Neuromuscular Synapse ◽  
Sexually Dimorphic ◽  
Intracellular Protein ◽  
Developmental Program ◽  
Androgen Action ◽  
Clawed Frog

Brain and muscle are sexually differentiated tissues in which masculinization is controlled by the secretion of androgens from the testes. Sensitivity to androgen is conferred by the expression of an intracellular protein, the androgen receptor. A central problem of sexual differentiation is thus to understand the cellular and molecular basis of androgen action. We do not understand how hormone occupancy of a receptor translates into an alteration in the developmental program of the target cell. Our studies on sexual differentiation of brain and muscle in Xenopus laevis are designed to explore the molecular basis of androgen induced sexual differentiation by examining how this hormone controls the masculinization of brain and muscle targets.Our approach to this problem has focused on a highly androgen sensitive, sexually dimorphic neuromuscular system: laryngeal muscles and motor neurons of the clawed frog, Xenopus laevis. We have been studying sex differences at a synapse, the laryngeal neuromuscular junction, which mediates sexually dimorphic vocal behavior in Xenopus laevis frogs.

A molecular basis for opiate action

1998 ◽  
Vol 33 ◽  
pp. 65-77 ◽  
Author(s):  
Dominique Massotte ◽  
Brigitte L. Kieffer
Keyword(s):  
Molecular Basis
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