Naslov
Chemical modification of low-density-lipoproteins enhances the number of binding-sites for divalent cations

Autori
Pifat, Greta ; Brnjas Kraljević, Jasminka ; Jurgens, Gerhard ; Herak Kramberger, C. ; Herak, Janko

Izvornik
Chemistry and Physics of Lipids (0009-3084) 63 (1992), 3; 159-167

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
massive cholesterol deposition; electron-spin-resonance; cell-surface receptors; lysine residues; apolipoprotein-B; mediates uptake; fibroblast; macrophages; degradation; oxidation

Sažetak
The EPR technique with paramagnetic Mn(II) ions has been used to probe the negatively charged sites on the surface of modified low-density lipoprotein (LDL). LDL modified in five different ways exhibited increased binding capacity for divalent cations. Enhanced binding is caused by the increase in the number of 'strong' binding sites. The 'strong' sites have been identified to be the aspartic acid and/or glutamic acid carboxyl residues and the 'weak' sites are zwitter-ionic phospholipids. In native LDL the negative groups make 'bonds' with the positive lysyl residues, thus stabilizing the structure. Any deprotonation or modification of the lysine amino groups makes the LDL structure more loose and the amino acid carboxyl groups accessible to divalent cations.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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