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Protein-Carbohydrate Interactions: Deoxylactosides as probes for the bindingspecificity of betha-galactoside binding lectin.

Ekberg, Tomas (1996)
Abstract
a) The use of a solid phase reaction (silver silicate) for avoiding ortho ester formation in some difficult glycosyl donor/acceptor systems. Thus seven monodeoxygenated analogues of 2-(Trimethylsilyl)ethyl betha-lactoside were synthesiszed. Silver silcate was successfully used in betha 1-4 coupling of 2- and 3-deoxy glucosides to to acetobromogalactose. By similar means, the monodeoxylactosyl bromides and acetates were coupled to azidosphingosine. Yhe yields of betha-lactosides were higher than 70% in all cases except the 2-deoxylactoside, that was transformed to the alpha-chloride and then betha-sphingosinylated over silver silicate in 45% yield.



b) The use of deoxylactosides as probes for investigating binding... (More)
a) The use of a solid phase reaction (silver silicate) for avoiding ortho ester formation in some difficult glycosyl donor/acceptor systems. Thus seven monodeoxygenated analogues of 2-(Trimethylsilyl)ethyl betha-lactoside were synthesiszed. Silver silcate was successfully used in betha 1-4 coupling of 2- and 3-deoxy glucosides to to acetobromogalactose. By similar means, the monodeoxylactosyl bromides and acetates were coupled to azidosphingosine. Yhe yields of betha-lactosides were higher than 70% in all cases except the 2-deoxylactoside, that was transformed to the alpha-chloride and then betha-sphingosinylated over silver silicate in 45% yield.



b) The use of deoxylactosides as probes for investigating binding selectivities in a low affinity lectin-sugar system (complexation of lactose by Erythrina corallodendron lectin, the Lac-EcorL interaction). The Lac-EcorL interaction was studied by titration microcalorimetry, and a competitive inhibition assay where EcorL binding to lymphocytes was measured with a fluorescence activated cell sorter (FACS). The 3'- , 4'- and 6'-deoxylactoside was inactive, whereas the other monodeoxylactosides retained their activity. These tesults correlate well with published X-ray chrystallographic data. Our measurements showed that LacNAc binds about 15 times stronger than lactose.



c) Computer simulations of the EcorL-Lac and EcorL-NAcLac complexes showed only minor differences concerning their hydrogen bonding properties. Interestingly, Lac O-3', O-4' seems to interact with both side chain oxygens in asp89 whereas only one of the oxygens was involved in binding to LacNAc. (Less)
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author
opponent
  • van Boeckel, Constant, NV Organon, Oss, Netherlands
publishing date
type
Thesis
publication status
published
subject
keywords
Organic chemistry, molecular modelling, calorimetry, competitive inhibition, molecular recognition, lectin, Erythrina corallodendron, glycoside synthesis, Lactose analogues, lactosyl ceramide, Organisk kemi
pages
130 pages
publisher
Organic Chemistry, Lund University
defense location
Chemical Center, lecture hall C
defense date
1996-02-15 10:15
external identifiers
  • Other:ISRN: LUTKDH/(TKOK-1036)/1-130/(1996)
language
English
LU publication?
no
id
28bdfcef-fad4-4f9e-a6c9-228df44d65c5 (old id 27628)
date added to LUP
2007-06-05 14:50:36
date last changed
2016-09-19 08:45:12
@misc{28bdfcef-fad4-4f9e-a6c9-228df44d65c5,
  abstract     = {a) The use of a solid phase reaction (silver silicate) for avoiding ortho ester formation in some difficult glycosyl donor/acceptor systems. Thus seven monodeoxygenated analogues of 2-(Trimethylsilyl)ethyl betha-lactoside were synthesiszed. Silver silcate was successfully used in betha 1-4 coupling of 2- and 3-deoxy glucosides to to acetobromogalactose. By similar means, the monodeoxylactosyl bromides and acetates were coupled to azidosphingosine. Yhe yields of betha-lactosides were higher than 70% in all cases except the 2-deoxylactoside, that was transformed to the alpha-chloride and then betha-sphingosinylated over silver silicate in 45% yield.<br/><br>
<br/><br>
b) The use of deoxylactosides as probes for investigating binding selectivities in a low affinity lectin-sugar system (complexation of lactose by Erythrina corallodendron lectin, the Lac-EcorL interaction). The Lac-EcorL interaction was studied by titration microcalorimetry, and a competitive inhibition assay where EcorL binding to lymphocytes was measured with a fluorescence activated cell sorter (FACS). The 3'- , 4'- and 6'-deoxylactoside was inactive, whereas the other monodeoxylactosides retained their activity. These tesults correlate well with published X-ray chrystallographic data. Our measurements showed that LacNAc binds about 15 times stronger than lactose.<br/><br>
<br/><br>
c) Computer simulations of the EcorL-Lac and EcorL-NAcLac complexes showed only minor differences concerning their hydrogen bonding properties. Interestingly, Lac O-3', O-4' seems to interact with both side chain oxygens in asp89 whereas only one of the oxygens was involved in binding to LacNAc.},
  author       = {Ekberg, Tomas},
  keyword      = {Organic chemistry,molecular modelling,calorimetry,competitive inhibition,molecular recognition,lectin,Erythrina corallodendron,glycoside synthesis,Lactose analogues,lactosyl ceramide,Organisk kemi},
  language     = {eng},
  pages        = {130},
  publisher    = {ARRAY(0xb6b5c80)},
  title        = {Protein-Carbohydrate Interactions: Deoxylactosides as probes for the bindingspecificity of betha-galactoside binding lectin.},
  year         = {1996},
}