scholarly journals Photodynamic Control of the Chain Length in Supramolecular Polymers: Switching an Intercalator into a Chain Capper

2020 ◽  
Vol 142 (13) ◽  
pp. 6295-6303 ◽  
Author(s):  
Elisabeth Weyandt ◽  
Gijs M. ter Huurne ◽  
Ghislaine Vantomme ◽  
Albert J. Markvoort ◽  
Anja R. A. Palmans ◽  
...  
Keyword(s):  
Chain Length ◽  
Supramolecular Polymers ◽  
A Chain ◽  
Photodynamic Control

Orthogonal chain length control in calix[5]arene-based AB-type supramolecular polymers

2011 ◽  
Vol 52 (48) ◽  
pp. 6460-6464 ◽  
Author(s):  
Claudia Gargiulli ◽  
Giuseppe Gattuso ◽  
Anna Notti ◽  
Sebastiano Pappalardo ◽  
Melchiorre F. Parisi
Keyword(s):  
Chain Length ◽  
Supramolecular Polymers

Mean Chain Length of Adsorbed Supramolecular Polymers

2006 ◽  
Vol 96 (7) ◽  
Author(s):  
Henk J. A. Zweistra ◽  
N. A. M. Besseling
Keyword(s):  
Chain Length ◽  
Supramolecular Polymers

scholarly journals The relationship between lymphangion chain length and maximum pressure generation established through in vivo imaging and computational modeling

2017 ◽  
Vol 313 (6) ◽  
pp. H1249-H1260 ◽  
Author(s):  
Mohammad S. Razavi ◽  
Tyler S. Nelson ◽  
Zhanna Nepiyushchikh ◽  
Rudolph L. Gleason ◽  
J. Brandon Dixon
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Minimally Invasive ◽  
Chain Length ◽  
Maximum Pressure ◽  
Computational Simulations ◽  
A Chain ◽  
Lymphatic Pumping ◽  
The Relationship

The intrinsic contraction of collecting lymphatic vessels serves as a pumping system to propel lymph against hydrostatic pressure gradients as it returns interstitial fluid to the venous circulation. In the present study, we proposed and validated that the maximum opposing outflow pressure along a chain of lymphangions at which flow can be achieved increases with the length of chain. Using minimally invasive near-infrared imaging to measure the effective pumping pressure at various locations in the rat tail, we demonstrated increases in pumping pressure along the length of the tail. Computational simulations based on a microstructurally motivated model of a chain of lymphangions informed from biaxial testing of isolated vessels was used to provide insights into the pumping mechanisms responsible for the pressure increases observed in vivo. These models suggest that the number of lymphangions in the chain and smooth muscle cell force generation play a significant role in determining the maximum outflow pressure, whereas the frequency of contraction has no effect. In vivo administration of nitric oxide attenuated lymphatic contraction, subsequently lowering the effective pumping pressure. Computational simulations suggest that the reduction in contractile strength of smooth muscle cells in the presence of nitric oxide can account for the reductions in outflow pressure observed along the lymphangion chain in vivo. Thus, combining modeling with multiple measurements of lymphatic pumping pressure provides a method for approximating intrinsic lymphatic muscle activity noninvasively in vivo while also providing insights into factors that determine the extent that a lymphangion chain can transport fluid against an adverse pressure gradient. NEW & NOTEWORTHY Here, we report the first minimally invasive in vivo measurements of the relationship between lymphangion chain length and lymphatic pumping pressure. We also provide the first in vivo validation of lumped parameter models of lymphangion chains previously developed through data obtained from isolated vessel testing.

scholarly journals The mitogenic activities of phosphatidate are acyl-chain-length dependent and calcium independent in C3H/10T1/2 cells.

1991 ◽  
Vol 2 (1) ◽  
pp. 57-64 ◽  
Author(s):  
M J Krabak ◽  
S W Hui
Keyword(s):  
Fatty Acid ◽  
Dna Synthesis ◽  
Chain Length ◽  
Acyl Chain ◽  
Calcium Transient ◽  
Signaling Mechanism ◽  
Acyl Chain Length ◽  
Dose Dependent Fashion ◽  
Continuous Presence ◽  
A Chain

Phosphatidates (PA or phosphatidic acid) were shown to have mitogenic properties, including the stimulation of DNA synthesis and calcium mobilization in C3H/10T1/2 cells. Their continuous presence for a minimum of 7 h induced DNA synthesis with kinetics similar to that observed when 10% fetal bovine serum was used as a mitogen. PAs with long chain saturated fatty acid moieties were more mitogenic, in a dose-dependent fashion, than PAs with short saturated or unsaturated fatty acid moieties. When compared with lysostearoyl-PA (LSPA), distearoyl-PA (DSPA) was as potent with respect to the induction of DNA synthesis. Lysooleoyl-PA (LOPA) was slightly more potent than dioleoyl-PA (DOPA), but much weaker than DSPA and LSPA. Preincubation with dilauroyl-PA (DLPA) reduces the mitogenic effect of DSPA by 85%. The pattern of mitogenic inhibition suggests that a chain-length-independent, yet PA-specific, mechanism is involved. Both DSPA and DLPA are equally taken up by the cells after 30 min. LOPA, but not LSPA, produced a large calcium transient (1.3 microM), which we found to be derived from intracellular sources. DSPA, the most mitogenic PA tested, produced a weaker transient (0.6 microM). Interestingly, LSPA did not produce any detectable calcium transient. These results suggest that the chain-length-specific step in the signaling mechanism of PA occurs after the initial chain-length-independent partitioning and/or binding to the membrane and that the induction of DNA synthesis is not related to the observed calcium transients.

Glycosylinositol phosphoceramide-specific phospholipase D activity catalyzes transphosphatidylation

2019 ◽  
Vol 166 (5) ◽  
pp. 441-448 ◽  
Author(s):  
Rumana Yesmin Hasi ◽  
Makoto Miyagi ◽  
Katsuya Morito ◽  
Toshiki Ishikawa ◽  
Maki Kawai-Yamada ◽  
...  
Keyword(s):  
Chain Length ◽  
Phospholipase D ◽  
Secondary Alcohol ◽  
Primary Alcohol ◽  
Tertiary Alcohol ◽  
Head Group ◽  
Polar Head Group ◽  
Polar Head ◽  
A Chain ◽  
Sugar Chains

Abstract Glycosylinositol phosphoceramide (GIPC) is the most abundant sphingolipid in plants and fungi. Recently, we detected GIPC-specific phospholipase D (GIPC-PLD) activity in plants. Here, we found that GIPC-PLD activity in young cabbage leaves catalyzes transphosphatidylation. The available alcohol for this reaction is a primary alcohol with a chain length below C4. Neither secondary alcohol, tertiary alcohol, choline, serine nor glycerol serves as an acceptor for transphosphatidylation of GIPC-PLD. We also found that cabbage GIPC-PLD prefers GIPC containing two sugars. Neither inositol phosphoceramide, mannosylinositol phosphoceramide nor GIPC with three sugar chains served as substrate. GIPC-PLD will become a useful catalyst for modification of polar head group of sphingophospholipid.

scholarly journals Purification, properties and cellular localization of the stereospecific CS2 secondary alkylsulphohydrolase of Comamonas terrigena

1977 ◽  
Vol 167 (3) ◽  
pp. 723-729 ◽  
Author(s):  
G W J Matcham ◽  
K S Dodgson ◽  
J W Fitzgerald
Keyword(s):  
Chain Length ◽  
Cellular Localization ◽  
Indirect Evidence ◽  
Initial Study ◽  
Potassium Salts ◽  
Experimental Conditions ◽  
Alkyl Sulphate ◽  
A Subunit ◽  
A Chain ◽  
Comamonas Terrigena

The availability of homogeneous samples of the potassium salts of L- and D-octan-2-yl sulphate has enabled the separation of the optically stereospecific CS1 and CS2 secondary alkysulphohydrolases from extracts of cells of Comamonas terrigena. The CS2 enzyme was purified to homogeneity, and an initial study was made of its general properties, specificity, cellular localization and relationship to the CS1 enzyme. The CS2 enzyme has a molecular weight of approx. 250000 and a subunit size of approx. 58000, indicating that the molecule is a tetramer. Under the experimental conditions used the enzyme appears to be specific for (+)-secondary alkyl sulphate esters with the sulphate group at C-2 and with a chain length of at least six carbons. Enzyme activity towards racemic C-2 sulphates increases with increasing chain length up to C10, and there is some indirect evidence to suggest that activity declines when that chain length is exceeded. Other indirect evidence confirms that the CS1 enzyme exhibits similar specificity, except that only (-)-isomers can serve as substrates. Both enzymes are present in broth-grown stationary-phase cells of C. terrigena in approximately equal amounts.

Evidence for a mevalonate shunt in a tracheophyte

1985 ◽  
Vol 225 (1241) ◽  
pp. 425-444 ◽  
Keyword(s):  
Chain Length ◽  
Length Distribution ◽  
Specific Inhibitor ◽  
Leaf Tissue ◽  
Acetate Incorporation ◽  
Wheat Seedlings ◽  
Chain Length Distribution ◽  
A Chain ◽  
Coa Reductase ◽  
A Minor

Primary leaf tissue from light and dark grown wheat seedlings incubated with [2- 14 C]acetate and [2- 3 H]mevalonolactone (MVA) synthesized doubly labelled sterols and long chain fatty alcohols (LCFA). While [2- 3 H]MVA was incorporated into LCFA as efficiently as into sterols, [5- 3 H]MVA was metabolized only to sterols. Mevinolin, a specific inhibitor of HMG–CoA reductase, completely inhibited [2- 14 C]acetate incorporation into sterols but it did not completely prevent [2- 3 H]MVA from being incorporated into LCFA. In the presence and absence of mevinolin, 3 H in the purified LCFA was found associated primarily with C 22 , C 24 , and C 26 (components isolated from the subcellular membranes), while 14 C was present additionally in C 28 (the major LCFA isolated from the epicuticular wax). Substantial 14 C and 3 H was incorporated into the membrane-bound 24-desalkyl and 24-alkylsterols with no loss of label associated with increasing the side chain length, that is, by alkylation at C 24 . The results demonstrate for the first time that: (i) the MVA shunt operates in a tracheophyte; (ii) preferential utilization of acetate, formed by the shunt and presumably compartmentalized, may exist in wheat for the synthesis of LCFA having a chain length distribution more suitable for membrane than wax construction; and (iii) the MVA shunt is not a minor vestigial lipid pathway but may, under certain physiological and developmental conditions, represent a pathway for routing isopentenyl pyrophosphate C-atoms away from their inclusion into the sterol pathway. Photosynthesis had no apparent effect on shunt activity.

1H-NMR spectra of all diastereomeric nitroalditols with a chain length up to C7, obtained from aldoses by the Fischer-Sowden reaction

1991 ◽  
Vol 1991 (3) ◽  
pp. 207-211 ◽  
Author(s):  
Peter Köll ◽  
Heinz Brandenburg ◽  
Willi Seelhorst ◽  
Claudia Stenns ◽  
Heide Kogelberg
Keyword(s):  
Chain Length ◽  
1H Nmr ◽  
Nmr Spectra ◽  
1H Nmr Spectra ◽  
A Chain
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