scholarly journals Structural requirements for active intestinal sugar transport. The involvement of hydrogen bonds at C-1 and C-6 of the sugar

1968 ◽  
Vol 109 (1) ◽  
pp. 61-67 ◽  
Author(s):  
J. E. G. Barnett ◽  
W. T. S. Jarvis ◽  
K A Munday
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Active Transport ◽  
Transport Process ◽  
Sugar Transport ◽  
Ideal Structure ◽  
Rat Intestine ◽  
Structural Requirements ◽  
The Ideal ◽  
Active Accumulation

1. A series of d-galactose derivatives substituted at C-1 and C-6 were tested for active accumulation by everted segments of hamster and rat intestine. 2. d-Galactose and 6-deoxy-6-fluoro-d-galactose were accumulated far more rapidly than 6-deoxy- and 6-chloro-6-deoxy-d-galactose, and this is interpreted as due to hydrogen-bonding at C-6 during the transport process. 3. 6-Bromo-6-deoxy- and 6-deoxy-6-iodo-d-galactose were not actively transported, indicating that the allowed size of substituent at C-6 lies between that of chlorine and bromine atoms. 4. Similar results were obtained at C-1. Both methyl α-d-galactopyranoside and methyl β-d-galactopyranoside were well transported, but methyl β-d-thiogalactopyranoside and 1-deoxy-d-galactose were not transported; d-galactopyranosyl fluoride was transported, but only poorly. Again hydrogen-bonding is suggested. 5. It is proposed that d-glucose is the ideal structure for active transport and that binding occurs at C-1, C-2, C-3, C-4 and C-6. Loss of two or more of these bonds usually causes loss of active transport. 6. By plotting Lineweaver–Burk plots of the rates of transport of the galactose derivatives, the apparent V and Km values were obtained. With hamster intestine both these values were very reproducible. Contrary to expectation, V varied for different sugars. 7. The Ki of some of the analogues modified at C-1 and C-6 was determined with methyl α-d-glucoside as substrate. 8. An attempt to alkylate the carrier by using methyl 3,4-anhydro-α-d-galactoside was unsuccessful. There was no evidence that this compound was bound to the carrier.

Renal sugar transport in the winter flounder. III. Two glucose transport systems

1977 ◽  
Vol 232 (3) ◽  
pp. F227-F234 ◽  
Author(s):  
A. Kleinzeller ◽  
G. R. Dubyak ◽  
P. M. Griffin ◽  
E. M. McAvoy ◽  
J. M. Mullin ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Glucose Transport ◽  
Transport System ◽  
Sugar Transport ◽  
Winter Flounder ◽  
Transport Systems ◽  
Renal Tubules ◽  
Pyranose Ring ◽  
Structural Requirements ◽  
Specificity Pattern

Teased renal tubules of the winter flounder (Pseudopleuronectes americanus) were employed to investigate the structural requirements for two pathways of D-glucose transport which take place preponderantly across the basal (antiluminal) face of renal cells. 1) An inhibition analysis of the equilibrating, Na-independent and phlorizin-sensitive transport of the nonmetabolizable methyl-alpha-D-glucoside (0.1 and 0.5 mM), with 20 glucose analogs (5 mM), was employed to establish the structural requirements for the substrate-carrier interaction: a (pyranose) ring, oxygen, or F at C1, C2-OH, C3-OH, and C4-OH (all axial, 1C model). Some interaction may also occur at C6-OH. D-Glucose shares this transport system. Hydrogen bonding between the oxygens and the carrier is suggested. 2) The phloretin- and phlorizin-sensitive, ouabain-insensitive transport of D-glucose, 2-deoxy-D-glucose, and D-mannose is associated with considerable phosphorylation. The three sugars mutually compete for a shared transport site. The specificity pattern characterizing the transport system defines the following structural requirements: a (pyranose) ring, a free C1-OH, C3-OH, and C4-OH (both axial) and possibly C6-OH. Hydrogen bonding between the carrier and the oxygens at C3, C4, and C6, and covalent bonding at C1 is suggested.

scholarly journals Hydrogen Bonds: Raman Spectroscopic Study

2021 ◽  
Vol 22 (10) ◽  
pp. 5380
Author(s):  
Boris A. Kolesov
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Spectroscopic Study ◽  
Raman Spectra ◽  
Temperature Region ◽  
Vibrational Frequency ◽  
Chemical Compounds ◽  
Raman Spectroscopic ◽  
Raman Spectroscopic Study ◽  
Proton Dynamics

The work outlines general ideas on how the frequency and the intensity of proton vibrations of X–H×××Y hydrogen bonding are formed as the bond evolves from weak to maximally strong bonding. For this purpose, the Raman spectra of different chemical compounds with moderate, strong, and extremely strong hydrogen bonds were obtained in the temperature region of 5 K–300 K. The dependence of the proton vibrational frequency is schematically presented as a function of the rigidity of O-H×××O bonding. The problems of proton dynamics on tautomeric O–H···O bonds are considered. A brief description of the N–H···O and C–H···Y hydrogen bonds is given.

The ideal structure of XX

1984 ◽  
Vol 30 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Neil Hindman ◽  
Paul Milnes
Keyword(s):  
Ideal Structure ◽  
The Ideal

scholarly journals Falling -Ideals in -Algebras

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Young Bae Jun ◽  
Sun Shin Ahn ◽  
Kyoung Ja Lee
Keyword(s):  
Theoretical Approach ◽  
Ideal Structure ◽  
Fundamental Properties ◽  
The Ideal

Based on the theory of a falling shadow which was first formulated by Wang (1985), a theoretical approach of the ideal structure in -algebras is established. The notions of a falling -subalgebra, a falling -ideal, a falling -ideal, and a falling -ideal of a -algebra are introduced. Some fundamental properties are investigated. Relations among a falling -subalgebra, a falling -ideal, a falling -ideal, and a falling -ideal are stated. Characterizations of falling -ideals and falling -ideals are discussed. A relation between a fuzzy -subalgebra and a falling -subalgebra is provided.

2-Hydroxy-3-methoxybenzaldehyde (pyridinium-4-ylcarbonyl)hydrazone chloride hemihydrate

2006 ◽  
Vol 62 (5) ◽  
pp. o2043-o2044 ◽  
Author(s):  
Shao-Wen Chen ◽  
Han-Dong Yin ◽  
Da-Qi Wang ◽  
Xia Kong ◽  
Xiao-Fang Chen
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Compound C

The crystal structure of the title compound, C14H14ClN3O3 +·Cl−·0.5H2O, exhibits O—H...O, C—H...O, C—H...Cl, N—H...Cl and O—H...Cl hydrogen bonds. The chloride anions participate in extensive hydrogen bonding with the aminium cations and link molecules through multiple N—H+...Cl− interactions.

A nuclear localization signal can enhance both the nuclear transport and expression of 1 kb DNA

1999 ◽  
Vol 112 (12) ◽  
pp. 2033-2041
Author(s):  
J.J. Ludtke ◽  
G. Zhang ◽  
M.G. Sebestyen ◽  
J.A. Wolff
Keyword(s):  
Active Transport ◽  
Nuclear Localization ◽  
Transport Process ◽  
Nuclear Transport ◽  
Passive Diffusion ◽  
Viral Gene ◽  
Nuclear Localization Signals ◽  
Size Limit ◽  
Cytosolic Extract ◽  
Active Transport Process

Although the entry of DNA into the nucleus is a crucial step of non-viral gene delivery, fundamental features of this transport process have remained unexplored. This study analyzed the effect of linear double stranded DNA size on its passive diffusion, its active transport and its NLS-assisted transport. The size limit for passive diffusion was found to be between 200 and 310 bp. DNA of 310–1500 bp entered the nuclei of digitonin treated cells in the absence of cytosolic extract by an active transport process. Both the size limit and the intensity of DNA nuclear transport could be increased by the attachment of strong nuclear localization signals. Conjugation of a 900 bp expression cassette to nuclear localization signals increased both its nuclear entry and expression in microinjected, living cells.

scholarly journals The ideal structure of the Hecke $C^*$ -algebra of Bost and Connes

2000 ◽  
Vol 318 (3) ◽  
pp. 433-451 ◽  
Author(s):  
Marcelo Laca ◽  
Iain Raeburn
Keyword(s):  
Ideal Structure ◽  
C Algebra ◽  
The Ideal

Five pseudopolymorphs of 6-amino-2-thiouracil: absence of N—H...S hydrogen bonds

2012 ◽  
Vol 69 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Wilhelm Maximilian Hützler ◽  
Michael Bolte
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Cambridge Structural Database ◽  
Hydrogen Bonding Pattern ◽  
Crystallization Experiments ◽  
Structural Database ◽  
Thiouracil Derivatives

In order to study the preferred hydrogen-bonding pattern of 6-amino-2-thiouracil, C4H5N3OS, (I), crystallization experiments yielded five different pseudopolymorphs of (I), namely the dimethylformamide disolvate, C4H5N3OS·2C3H7NO, (Ia), the dimethylacetamide monosolvate, C4H5N3OS·C4H9NO, (Ib), the dimethylacetamide sesquisolvate, C4H5N3OS·1.5C4H9NO, (Ic), and two different 1-methylpyrrolidin-2-one sesquisolvates, C4H5N3OS·1.5C5H9NO, (Id) and (Ie). All structures containR21(6) N—H...O hydrogen-bond motifs. In the latter four structures, additionalR22(8) N—H...O hydrogen-bond motifs are present stabilizing homodimers of (I). No type of hydrogen bond other than N—H...O is observed. According to a search of the Cambridge Structural Database, most 2-thiouracil derivatives form homodimers stabilized by anR22(8) hydrogen-bonding pattern, with (i) only N—H...O, (ii) only N—H...S or (iii) alternating pairs of N—H...O and N—H...S hydrogen bonds.

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