scholarly journals Development And Characterization Of Fluorescent Mannose- And Sialic Acid Based Chemical Probes For Lectin Discovery And Enzyme Studies

Author(s):  
Tasnim Abukar

BODIPY (4,4–Difluoro-4-boro-3a,4a-diaza-s-indacene) dyes are relatively nonpolar fluorescent molecules used as biological labeling reagents. The advantages of using BODIPY dyes as tags include their unique photochemical properties, allowing for an easy and sensitive monitoring of target components. This thesis will discuss the synthesis of novel fluorescent “BODIPY”-labeled carbohydrate-based chemical probes and highlight their uses in different biological applications. In chapter one, we have focused on the development of BODIPY-mannose-based chemical probes for the discovery and characterization of mannose-binding lectins on surfaces of Actinobacteria. The synthesis of these probes and their efficiency to detect mannose-binding lectins using different techniques such as Fluorescence microscopy and flow cytometry are discussed. In chapter two, we have focused on the chemo-enzymatic synthesis of BODIPY-sialic acid based chemical probes for enzymatic detection of specific glycoconjugates on proteins. The use of these probes as donor substrates to probe the enzymes involved in glycan sialylation are discussed

2021 ◽  
Author(s):  
Tasnim Abukar

BODIPY (4,4–Difluoro-4-boro-3a,4a-diaza-s-indacene) dyes are relatively nonpolar fluorescent molecules used as biological labeling reagents. The advantages of using BODIPY dyes as tags include their unique photochemical properties, allowing for an easy and sensitive monitoring of target components. This thesis will discuss the synthesis of novel fluorescent “BODIPY”-labeled carbohydrate-based chemical probes and highlight their uses in different biological applications. In chapter one, we have focused on the development of BODIPY-mannose-based chemical probes for the discovery and characterization of mannose-binding lectins on surfaces of Actinobacteria. The synthesis of these probes and their efficiency to detect mannose-binding lectins using different techniques such as Fluorescence microscopy and flow cytometry are discussed. In chapter two, we have focused on the chemo-enzymatic synthesis of BODIPY-sialic acid based chemical probes for enzymatic detection of specific glycoconjugates on proteins. The use of these probes as donor substrates to probe the enzymes involved in glycan sialylation are discussed


2021 ◽  
Vol 10 (8) ◽  
pp. 1661
Author(s):  
Andrés Ramírez-López ◽  
María Teresa Álvarez Román ◽  
Elena Monzón Manzano ◽  
Paula Acuña ◽  
Elena G. Arias-Salgado ◽  
...  

Loss of sialic acid from the carbohydrate side chains of platelet glycoproteins can affect platelet clearance, a proposed mechanism involved in the etiopathogenesis of immune thrombocytopaenia (ITP). We aimed to assess whether changes in platelet glycosylation in patients with ITP affected platelet counts, function, and apoptosis. This observational, prospective, and transversal study included 82 patients with chronic primary ITP and 115 healthy controls. We measured platelet activation markers and assayed platelet glycosylation and caspase activity, analysing samples using flow cytometry. Platelets from patients with ITP with a platelet count <30 × 103/µL presented less sialic acid. Levels of α1,6-fucose (a glycan residue that can directly regulate antibody-dependent cellular cytotoxicity) and α-mannose (which can be recognised by mannose-binding-lectin and activate the complement pathway) were increased in the platelets from these patients. Platelet surface exposure of other glycoside residues due to sialic acid loss inversely correlated with platelet count and the ability to be activated. Moreover, loss of sialic acid induced the ingestion of platelets by human hepatome HepG2 cells. Changes in glycoside composition of glycoproteins on the platelets’ surface impaired their functional capacity and increased their apoptosis. These changes in platelet glycoside residues appeared to be related to ITP severity.


2003 ◽  
Vol 160 (8) ◽  
pp. 913-920 ◽  
Author(s):  
Yourong Chai ◽  
Yongzhen Pang ◽  
Zhihua Liao ◽  
L.e.i. Zhang ◽  
Xiaofen Sun ◽  
...  

1984 ◽  
Vol 62 (5) ◽  
pp. 276-279 ◽  
Author(s):  
C. H. Lin ◽  
W. Chung ◽  
K. P. Strickland ◽  
A. J. Hudson

An isozyme of S-adenosylmethionine synthetase has been purified to homogeneity by ammonium sulfate fractionation, DEAE-cellulose column chromatography, and gel filtration on a Sephadex G-200 column. The purified enzyme is very unstable and has a molecular weight of 120 000 consisting of two identical subunits. Amino acid analysis on the purified enzyme showed glycine, glutamate, and aspartate to be the most abundant and the aromatic amino acids to be the least abundant. It possesses tripolyphosphatase activity which can be stimulated five to six times by S-adenosylmethionine (20–40 μM). The findings support the conclusion that an enzyme-bound tripolyphosphate is an obligatory intermediate in the enzymatic synthesis of S-adenosylmethionine from ATP and methionine.


1985 ◽  
Vol 260 (8) ◽  
pp. 4941-4951
Author(s):  
D H Joziasse ◽  
M L Bergh ◽  
H G ter Hart ◽  
P L Koppen ◽  
G J Hooghwinkel ◽  
...  

Biochemistry ◽  
1972 ◽  
Vol 11 (14) ◽  
pp. 2559-2564 ◽  
Author(s):  
John F. Codington ◽  
Barbara H. Sanford ◽  
Roger W. Jeanloz

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