Catalysis of Thiol–Thioester Exchange by Water-Soluble Alkyldiselenols Applied to the Synthesis of Peptide Thioesters and SEA-Mediated Ligation

Abstract Identification of patterns in chemical reaction pathways aids in the effective design of molecules for specific applications. Here, we report on model reactions with a water-soluble single thiol-thioester exchange (TTE) reaction substrate, which was designed taking in view biological and medical applications. This substrate consists of the thio-depsipeptide, Ac-Pro-Leu-Gly-SLeu-Leu-Gly-NEtSH (TDP) and does not yield foul-smelling thiol exchange products when compared with aromatic thiol containing single TTE substrates. TDP generates an α,ω-dithiol crosslinker in situ in a ‘pseudo intramolecular’ TTE. Competitive intermolecular TTE of TDP with externally added “basic” thiols increased the crosslinker concentration whilst “acidic” thiols decreased its concentration. TDP could potentially enable in situ bioconjugation and crosslinking applications. Graphic abstract The competition between ‘pseudo intramolecular’ and intermolecular exchange of a peptide-based thiol-thioester exchange (TTE) substrate can be used to control the relative amount of final exchange products based on size and pKa values of externally added thiols. Potential application of this system can be seen in the development of TTE substrates for the rapid identification of thiols by dynamic combinatorial screening.

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A Resorcinol-Formaldehyde Resin as an Embedding Material for Electron Microscopy of Membranes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010006355x ◽

1969 ◽

Vol 27 ◽

pp. 328-329 ◽

Cited By ~ 1

Author(s):

J. G. Robertson ◽

D. F. Parsons

Keyword(s):

Electron Microscopy ◽

Osmium Tetroxide ◽

Neutral Lipids ◽

Lipid Extraction ◽

Water Soluble ◽

Formaldehyde Resin ◽

Electron Microscope Autoradiography ◽

Resorcinol Formaldehyde ◽

Major Disadvantage ◽

Cell Organization

The extraction of lipids from tissues during fixation and embedding for electron microscopy is widely recognized as a source of possible artifact, especially at the membrane level of cell organization. Lipid extraction is also a major disadvantage in electron microscope autoradiography of radioactive lipids, as in studies of the uptake of radioactive fatty acids by intestinal slices. Retention of lipids by fixation with osmium tetroxide is generally limited to glycolipids, phospholipids and highly unsaturated neutral lipids. Saturated neutral lipids and sterols tend to be easily extracted by organic dehydrating reagents prior to embedding. Retention of the more saturated lipids in embedded tissue might be achieved by developing new cross-linking reagents, by the use of highly water soluble embedding materials or by working at very low temperatures.

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Ferritin Labeled Antibody Staining of Thin Sections

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100064013 ◽

1969 ◽

Vol 27 ◽

pp. 420-421

Author(s):

J. D. McLean ◽

S. J. Singer

Keyword(s):

Biological Material ◽

Water Soluble ◽

Thin Sections ◽

Antibody Staining ◽

Thin Sectioning ◽

Ultrathin Sections

The successful application of ferritin labeled antibodies (F-A) to ultrathin sections of biological material has been hampered by two main difficulties. Firstly the normally used procedures for the preparation of material for thin sectioning often result in a loss of antigenicity. Secondly the polymers employed for embedding may non-specifically absorb the F-A. Our earlier use of cross-linked polyampholytes as embedding media partially overcame these problems. However the water-soluble monomers used for this method still extract many lipids from the material.

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The Effect of Benzene on Bluegill Olfactory Lamellae

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010011965x ◽

1985 ◽

Vol 43 ◽

pp. 574-575

Author(s):

D.R. Mattie ◽

J.W. Fisher

Keyword(s):

Surface Morphology ◽

Soluble Fraction ◽

Lepomis Macrochirus ◽

Sublethal Concentration ◽

Water Soluble ◽

Major Constituent ◽

Jet Fuels ◽

Aquatic Biota ◽

Normal Surface ◽

Cacodylate Buffer

Jet fuels such as JP-4 can be introduced into the environment and come in contact with aquatic biota in several ways. Studies in this laboratory have demonstrated JP-4 toxicity to fish. Benzene is the major constituent of the water soluble fraction of JP-4. The normal surface morphology of bluegill olfactory lamellae was examined in conjunction with electrophysiology experiments. There was no information regarding the ultrastructural and physiological responses of the olfactory epithelium of bluegills to acute benzene exposure.The purpose of this investigation was to determine the effects of benzene on the surface morphology of the nasal rosettes of the bluegill sunfish (Lepomis macrochirus). Bluegills were exposed to a sublethal concentration of 7.7±0.2ppm (+S.E.M.) benzene for five, ten or fourteen days. Nasal rosettes were fixed in 2.5% glutaraldehyde and 2.0% paraformaldehyde in 0.1M cacodylate buffer (pH 7.4) containing 1.25mM calcium chloride. Specimens were processed for scanning electron microscopy.

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An SEM study of raphide crystal initials in the leaves of vitis (grape)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100141299 ◽

1995 ◽

Vol 53 ◽

pp. 984-985

Author(s):

H. J. Arnott ◽

M. A. Webb ◽

L. E. Lopez

Keyword(s):

Calcium Oxalate ◽

Water Soluble ◽

Calcium Oxalate Crystals ◽

Calcium Oxalate Crystal ◽

Oxalate Crystals ◽

Large Numbers ◽

Sem Study ◽

The Matrix ◽

Crystal Cells ◽

Crystal Idioblast

Many papers have been published on the structure of calcium oxalate crystals in plants, however, few deal with the early development of crystals. Large numbers of idioblastic calcium oxalate crystal cells are found in the leaves of Vitis mustangensis, V. labrusca and V. vulpina. A crystal idioblast, or raphide cell, will produce 150-300 needle-like calcium oxalate crystals within a central vacuole. Each raphide crystal is autonomous, having been produced in a separate membrane-defined crystal chamber; the idioblast''s crystal complement is collectively embedded in a water soluble glycoprotein matrix which fills the vacuole. The crystals are twins, each having a pointed and a bidentate end (Fig 1); when mature they are about 0.5-1.2 μn in diameter and 30-70 μm in length. Crystal bundles, i.e., crystals and their matrix, can be isolated from leaves using 100% ETOH. If the bundles are treated with H2O the matrix surrounding the crystals rapidly disperses.

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Characterization of Chemical Impurities in Glutaraldehyde

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100116723 ◽

1975 ◽

Vol 33 ◽

pp. 620-621

Author(s):

B. J. Grenon ◽

A. J. Tousimis

Keyword(s):

Glutaric Acid ◽

Spectroscopic Analysis ◽

Aldol Condensation ◽

Condensation Product ◽

Amorphous Solid ◽

Water Soluble ◽

Impurity Component ◽

Chemical Impurities ◽

Soluble Liquid

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.

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Water-soluble amphiphilic ruthenium(ii) polypyridyl complexes as potential light-activated therapeutic agents

Chemical Communications ◽

10.1039/d0cc04397d ◽

2020 ◽

Vol 56 (65) ◽

pp. 9332-9335

Author(s):

Sandra Estalayo-Adrián ◽

Salvador Blasco ◽

Sandra A. Bright ◽

Gavin J. McManus ◽

Guillermo Orellana ◽

...

Keyword(s):

Cervical Cancer ◽

Cancer Cells ◽

Cellular Uptake ◽

Therapeutic Agents ◽

Water Soluble ◽

Polypyridyl Complexes ◽

Cervical Cancer Cells

Two new water-soluble amphiphilic Ru(ii) polypyridyl complexes were synthesised and their photophysical and photobiological properties evaluated; both complexes showed a rapid cellular uptake and phototoxicity against HeLa cervical cancer cells.

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Water soluble palladium(ii) and platinum(ii) acyclic diaminocarbene complexes: solution behavior, DNA binding, and antiproliferative activity

New Journal of Chemistry ◽

10.1039/d0nj00060d ◽

2020 ◽

Vol 44 (15) ◽

pp. 5762-5773 ◽

Cited By ~ 1

Author(s):

Tatiyana V. Serebryanskaya ◽

Mikhail A. Kinzhalov ◽

Vladimir Bakulev ◽

Georgii Alekseev ◽

Anastasiya Andreeva ◽

...

Keyword(s):

Dna Binding ◽

Antiproliferative Activity ◽

Water Soluble ◽

Solution Behavior ◽

Antitumor Potential ◽

Acyclic Diaminocarbene

Water soluble Pd(ii) and Pt(ii)–ADC species synthesized via the metal-mediated coupling of isocyanides and 1,2-diaminobenzene have demonstrated antitumor potential.

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