Teaming up synthetic chemistry and histochemistry for activity screening in galectin-directed inhibitor design
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- 作者：René Roy ; Yihong Cao ; Herbert Kaltner ; Naresh Kottari…
- 关键词：Agglutinin ; Glycocluster ; Glycoprotein ; Glycosylation ; Lectin
- 刊名：Histochemistry and Cell Biology
- 出版年：2017
- 出版时间：February 2017
- 年：2017
- 卷：147
- 期：2
- 页码：285-301
- 全文大小：
- 刊物类别：Medicine
- 刊物主题：Biomedicine, general; Cell Biology; Biochemistry, general; Developmental Biology;
- 出版者：Springer Berlin Heidelberg
- ISSN：1432-119X
- 卷排序：147
文摘
A hallmark of endogenous lectins is their ability to select a few distinct glycoconjugates as counterreceptors for functional pairing from the natural abundance of cellular glycoproteins and glycolipids. As a consequence, assays to assess inhibition of lectin binding should necessarily come as close as possible to the physiological situation, to characterize an impact of a synthetic compound on biorelevant binding with pharmaceutical perspective. We here introduce in a proof-of-principle manner work with sections of paraffin-embedded tissue (jejunum, epididymis) and labeled adhesion/growth-regulatory galectins, harboring one (galectin-1 and galectin-3) or two (galectin-8) types of lectin domain. Six pairs of synthetic lactosides from tailoring of the headgroup (3′-O-sulfation) and the aglycone (β-methyl to aromatic S- and O-linked extensions) as well as three bi- to tetravalent glycoclusters were used as test compounds. Varying extents of reduction in staining intensity by synthetic compounds relative to unsubstituted/free lactose proved the applicability and sensitivity of the method. Flanking cytofluorimetric assays on lectin binding to native cells gave similar grading, excluding a major impact of tissue fixation. The experiments revealed cell/tissue binding of galectin-8 preferentially via one domain, depending on the cell type so that the effect of an inhibitor in a certain context cannot be extrapolated to other cells/tissues. Moreover, the work with the other galectins attests that this assay enables comprehensive analysis of the galectin network in serial tissue sections to determine overlaps and regional differences in inhibitory profiles.