Biochemical Analyses of oli1 and oli2 Gene Mutations Determining Primary Sequence Changes in Subunits 9 and 6 of Yeast ATP Synthase

1989 ◽  
pp. 51-65
Author(s):  
Sybella Meltzer ◽  
Tracy A. Willson ◽  
Linton C. Watkins ◽  
Phillip Nagley ◽  
Sangkot Marzuki ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Gene Mutations ◽  
Primary Sequence ◽  
Biochemical Analyses

scholarly journals Structure and mechanism of the ATP synthase membrane motor inferred from quantitative integrative modeling

2016 ◽  
Vol 148 (6) ◽  
pp. 441-457 ◽  
Author(s):  
Vanessa Leone ◽  
José D. Faraldo-Gómez
Keyword(s):  
Atp Synthase ◽  
Binding Sites ◽  
Transmembrane Domain ◽  
Structural Information ◽  
Integrative Approach ◽  
Subunit A ◽  
C Complex ◽  
Biochemical Analyses ◽  
Correlated Mutation ◽  
Mutation Analyses

Two subunits within the transmembrane domain of the ATP synthase—the c-ring and subunit a—energize the production of 90% of cellular ATP by transducing an electrochemical gradient of H+ or Na+ into rotational motion. The nature of this turbine-like energy conversion mechanism has been elusive for decades, owing to the lack of definitive structural information on subunit a or its c-ring interface. In a recent breakthrough, several structures of this complex were resolved by cryo–electron microscopy (cryo-EM), but the modest resolution of the data has led to divergent interpretations. Moreover, the unexpected architecture of the complex has cast doubts on a wealth of earlier biochemical analyses conducted to probe this structure. Here, we use quantitative molecular-modeling methods to derive a structure of the a–c complex that is not only objectively consistent with the cryo-EM data, but also with correlated mutation analyses of both subunits and with prior cross-linking and cysteine accessibility measurements. This systematic, integrative approach reveals unambiguously the topology of subunit a and its relationship with the c-ring. Mapping of known Cd2+ block sites and conserved protonatable residues onto the structure delineates two noncontiguous pathways across the complex, connecting two adjacent proton-binding sites in the c-ring to the space on either side of the membrane. The location of these binding sites and of a strictly conserved arginine on subunit a, which serves to prevent protons from hopping between them, explains the directionality of the rotary mechanism and its strict coupling to the proton-motive force. Additionally, mapping of mutations conferring resistance to oligomycin unexpectedly reveals that this prototypical inhibitor may bind to two distinct sites at the a–c interface, explaining its ability to block the mechanism of the enzyme irrespective of the direction of rotation of the c-ring. In summary, this study is a stepping stone toward establishing the mechanism of the ATP synthase at the atomic level.

Visualization of the Platelet-Plasma Interface

1977 ◽  
Vol 35 ◽  
pp. 494-495
Author(s):  
D. C. Brindley ◽  
M. McGill
Keyword(s):  
Platelet Rich Plasma ◽  
Coagulation Factors ◽  
Platelet Membrane ◽  
Rabbit Platelet ◽  
Surface Coat ◽  
Special Relationship ◽  
Routine Method ◽  
Embedding Technique ◽  
Biochemical Analyses ◽  
Adsorptive Properties

Morphological and cytochemical studies of platelets have reported a surface coat, or glycocalyx, external to the plasma membrane (1). Biochemical analyses have likewise confirmed the highly adsorptive properties of platelets as transporters of coagulation factors (2). However, visualization of the platelet membrane by conventional EM procedures does not reflect this special relationship between the platelet and its plasma environment. By the routine method of alcohol-propylene oxide dehydration for Epon embedding, the lipid bilayer nature of the platelet membrane appears similar to other blood cells (Fig. 1). A new rapid embedding technique using dimethoxypropane (DMP) as dehydrating agent (13) has permitted ultrastructural analyses of the surface features of the platelet-plasma interface.Aliquots of human or rabbit platelet-rich plasma (PRP) were added to equal volumes of 6% glutaraldehyde in Millonig's buffer at 37° for 45 minutes, rinsed in buffer and postfixed in 1% osmium in Millonig's buffer for 45 minutes.

Morphological and biochemical analyses of changes in rat hepatocytes related to wine and ethanol consumption

1984 ◽  
Vol 42 ◽  
pp. 232-233
Author(s):  
S.M. Geyer ◽  
C.L. Mendenhall ◽  
J.T. Hung ◽  
E.L. Cardell ◽  
R.L. Drake ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Enzyme Activity ◽  
Malic Enzyme ◽  
Smooth Endoplasmic Reticulum ◽  
Rat Hepatocytes ◽  
Mature Male ◽  
Treatment Groups ◽  
Malic Enzyme Activity ◽  
Biochemical Analyses

Thirty-three mature male Holtzman rats were randomly placed in 3 treatment groups: Controls (C); Ethanolics (E); and Wine drinkers (W). The animals were fed synthetic diets (Lieber type) with ethanol or wine substituted isocalorically for carbohydrates in the diet of E and W groups, respectively. W received a volume of wine which provided the same gram quantity of alcohol consumed by E. The animals were sacrificed by decapitation after 6 weeks and the livers processed for quantitative triglycerides (T3), proteins, malic enzyme activity (MEA), light microscopy (LM) and electron microscopy (EM). Morphometric analysis of randomly selected LM and EM micrographs was performed to determine organellar changes in centrilobular (CV) and periportal (PV) regions of the liver. This analysis (Table 1) showed that hepatocytes from E were larger than those in C and W groups. Smooth endoplasmic reticulum decreased in E and increased in W compared to C values.

Combined defect in membrane expression and activation of platelet GPIIb-IIIa complex without primary sequence abnormalities in myeloproliferative disease

2000 ◽  
Vol 111 (3) ◽  
pp. 954-964 ◽  
Author(s):  
Robert Kaplan ◽  
Jagadeesh Gabbeta ◽  
Ling Sun ◽  
Guang Fen Mao ◽  
A. Koneti Rao
Keyword(s):  
Myeloproliferative Disease ◽  
Primary Sequence ◽  
Membrane Expression

WT1 GENE MUTATIONS IN DENYS‐DRASH AND FRASIER SYNDROME

Nephrology ◽  
2000 ◽  
Vol 5 (3) ◽  
pp. A110-A110
Author(s):  
McTaggart Sj ◽  
Algar E ◽  
Chow Cw ◽  
Powell Hr ◽  
Jones CL.
Keyword(s):  
Gene Mutations ◽  
Wt1 Gene ◽  
Frasier Syndrome

F-type or V-type? The chimeric nature of the archaebacterial ATP synthase

1992 ◽  
Vol 1101 (2) ◽  
pp. 232-235 ◽  
Author(s):  
G SCHAFER ◽  
M MEYERINGVOS
Keyword(s):  
Atp Synthase

1068: TP53 Gene Mutations as a Prognostic Marker for PSA Progression in Early Stage Prostate Cancer

2004 ◽  
Vol 171 (4S) ◽  
pp. 282-282
Author(s):  
Markus D. Sachs ◽  
Horst Schlechte ◽  
Katrin Schiemenz ◽  
Severin V. Lenk ◽  
Dietmar Schnorr ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Prognostic Marker ◽  
Early Stage ◽  
Gene Mutations ◽  
Tp53 Gene ◽  
Psa Progression ◽  
Tp53 Gene Mutations
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