Rotary replication for freeze-etching.

L H Margaritis; A Elgsaeter; D Branton

doi:10.1083/jcb.72.1.47

Home/Archive/PubMed

PubMed · 830655

Rotary replication for freeze-etching.

L H Margaritis·A Elgsaeter·D Branton

View original source ↗Export metadata ↓

Abstract

Rotary replication has been adapted to freeze-etching and evaluated using T4 polyheads, erythrocyte ghosts, and chloroplast membranes. Conventional electron microscopy, electron diffraction, and optical diffraction and filtering indicate that platinum-carbon rotary replication renders radially symmetrical contrast and 25 A resolution to freeze-etched specimens so as to clarify subunit structure not normally evident in unidirectional shadow replicas.

Explore related subjects

Carbon Chloroplasts Coliphages Erythrocyte Membrane Freeze Etching Membranes Platinum Journal Article Research Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

L H Margaritis, A Elgsaeter, D Branton. 1977. Rotary replication for freeze-etching.. https://doi.org/10.1083/jcb.72.1.47

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2025

Phenotypic profiling of carbon utilization of Pectobacterium brasiliense (Pbr1692).

Pectobacterium brasiliense 1692 (Pbr1692) is a necrotrophic pathogen that infects many crops such as potatoes and ornamental plants and derives nutrients from degraded plant tissue. Previous studies have identified Pbr1692 genes required for ecological fitness and virulence, however there is a lack of information on nutrient utilization in Pbr1692. Carbon source utilization profiling in Pbr1692 could provide a platform to decipher its metabolic flexibility and adaptation. This study assessed the nutrient utilization of Pbr1692 in different carbon sources, using Biolog Phenotypic Microarray (PM). An array of carbon sources utilized by Pbr1692 were identified, 32 carbohydrates and 8 carboxylic acids were among the preferred carbon nutrients utilized by Pbr1692. The PM results also revealed that the citric acid cycle, amino acid metabolism, and pentose phosphate metabolic pathways might be used to produce energy for Pbr1692. In addition, growth of Pbr1692 cells in minimal medium supplemented with citric acid, glucose, and aspartic acid retained the typical rod shape, suggesting that nutrient variation did not influence Pbr1692 cell morphology adaptation. This study provides an understanding on the adaptation of Pbr1692 and lays a foundation for understanding carbon metabolism of Pbr1692.

Carbon↗

PubMed2001

Discovery of a novel enzyme, isonitrile hydratase, involved in nitrogen-carbon triple bond cleavage.

Isonitrile containing an N triple bond C triple bond was degraded by microorganism sp. N19-2, which was isolated from soil through a 2-month acclimatization culture in the presence of this compound. The isonitrile-degrading microorganism was identified as Pseudomonas putida. The microbial degradation was found to proceed through an enzymatic reaction, the isonitrile being hydrated to the corresponding N-substituted formamide. The enzyme, named isonitrile hydratase, was purified and characterized. The native enzyme had a molecular mass of about 59 kDa and consisted of two identical subunits. The enzyme stoichiometrically catalyzed the hydration of cyclohexyl isocyanide (an isonitrile) to N-cyclohexylformamide, but no formation of other compounds was detected. The apparent K(m) value for cyclohexyl isocyanide was 16.2 mm. Although the enzyme acted on various isonitriles, no nitriles or amides were accepted as substrates.

Carbon↗

PubMed2001

Conformational properties of alpha-synuclein in its free and lipid-associated states.

alpha-Synuclein (alphaS) is a presynaptic terminal protein that is believed to play an important role in the pathogenesis of Parkinson's disease (PD). We have used NMR spectroscopy to characterize the conformational properties of alphaS in solution as a free monomer and when bound to lipid vesicles and lipid-mimetic detergent micelles. Free wild-type alphaS is largely unfolded in solution, but exhibits a region with a preference for helical conformations that may be important in the aggregation of alphaS into fibrils. The N-terminal region of alphaS binds to synthetic lipid vesicles and detergent micelles in vitro and adopts a highly helical conformation, consistent with predictions based on sequence analysis. The C-terminal part of the protein does not associate with either vesicles or micelles, remaining free and unfolded. These results suggest that one function of alphaS may be to tether as of yet unidentified partners to lipid surfaces via interactions with its C-terminal tail.

Carbon↗