Related Experiment Videos
Human plasma trans-sialidase donor and acceptor specificity.
V V Tertov1, E Yu Nikonova, N E Nifant'ev
1Institute of Experimental Cardiology, Cardiology Research Center, Russian Academy of Medical Sciences, Moscow, 121552 Russia. inat@cardio.ru
Biochemistry. Biokhimiia
|September 12, 2002
Summary
Human plasma contains a trans-sialidase enzyme that transfers sialic acids. This enzyme moves sialic acids from various molecules to desialylated low-density lipoproteins (dLDL), a key factor in atherosclerosis.
Area of Science:
- Biochemistry
- Glycobiology
- Lipid Metabolism
Background:
- Desialylated low-density lipoproteins (dLDL) induce cholesterol ester accumulation, a process linked to atherosclerosis.
- Lipoprotein desialylation occurs in human plasma, with removed sialic acids transferring to other serum glycoconjugates.
Purpose of the Study:
- To isolate and characterize a human plasma enzyme responsible for sialic acid transfer.
- To investigate the donor and acceptor specificity of this plasma trans-sialidase.
Main Methods:
- Isolation of trans-sialidase from human plasma using affinity chromatography.
- Enzymatic assays to determine substrate specificity with various lipoproteins, glycoproteins, and gangliosides.
Main Results:
- A trans-sialidase was isolated from human plasma.
- The enzyme transfers sialic acids (alpha2-6, alpha2-3, and alpha2-8 linkages) from various donors including lipoproteins, glycoproteins, and gangliosides.
- Desialylated lipoproteins, particularly dLDL, are preferred acceptors for sialic acid transfer.
Conclusions:
- Human plasma possesses a trans-sialidase capable of modifying lipoproteins.
- The enzyme's activity may play a role in the dynamic transfer of sialic acids in serum, potentially influencing dLDL metabolism and atherosclerosis development.