CEC: A tool for mimicking collagen–surface interactions with apolipoprotein B‐100 peptides

Abstract

Collagens I and III are involved in the formation of the extracellular matrix and presumably in the development of several diseases, such as atherosclerosis. In this study, stable collagen and collagen-decorin coatings were prepared on the inner surfaces of fused silica CEC capillaries, enabling study of the interactions between collagen and selected peptide fragments of apolipoprotein B-100 (apoB-100), the main protein of low-density lipoprotein (LDL) particles. Interactions of positive, neutral, and negative peptide fragments of apoB-100 were elucidated. The selected positive peptide contains the sequence involved in the interaction of LDL with LDL receptor and proteoglycans. Retention factors of the peptides that were determined without any voltage, by exploiting pressure, gave numerical information about interactions with the collagen coatings. The inclusion of decorin in the coatings confirmed the importance of glycosaminoglycans in mediating the interactions between collagens and apoB-100 peptide fragments. The studies support earlier findings that collagens I and III take part in the retention of LDL particles in the intima through binding with a specific positive site on apoB-100. The method developed is simple, but also inexpensive since only small amounts of peptides and collagens are required. Atomic force microscopy images provided valuable information about the topography of collagen and collagen-decorin coatings on the capillary wall.

Sugar treatment of human lipoprotein particles and their separation by capillary electrophoresis

“…For this purpose, we selected one peptide sequence of apolipoprotein B‐100 (peptide 1) and one sequence of apolipoprotein E (peptide 2). The selected peptides were also used in our earlier interaction studies with extracellular matrix components 34. The sugars were cyclic isomers of glucose, maltose and sucrose.…”

Open tubular capillary electrochromatography: A useful microreactor for collagen I glycation and interaction studies with low-density lipoprotein particles

“…Changes in the RSD values of the EOF mobilities before and after glycation were caused most probably by slight variations in collagen I coatings [25]. The data showed that the mobility augments after the glycation, and the increase is proportional to the glycation time (Table 1).…”

“…Collagen I coating was already optimized in our earlier work [25]. Before coating, a bare fused silica capillary (L tot 38.5 cm; L det 30 cm) was preconditioned by flushing 20 min with 1 M HCl, 10 min with 0.1 M HCl, 25 min with Milli-Q water, and 5 min with BGE at pH 7.4.…”

“…As shown in our previous papers, CEC can serve as an excellent platform for surface interaction studies [22][23][24][25]. LDLs, very low-density lipoproteins (VLDLs), high-density lipoproteins (HDLs), and collagen I and III were immobilized on the inner wall of fused silica capillary as stationary phase, and employed for interaction studies with biological markers.…”

“…Since LDLs interact with the various ECM components via their major and sole protein, the apolipoprotein B-100 (apoB-100), selected peptide fragments of apoB-100 were injected as control. The criteria for the selection of the positively charged (PP) and electroneutral peptide (NeuP 2 ) have been fully defined in our previous work [25]. Briefly, PP, which consists of 19 amino acids, has a net charge of +6 at pH 7.4 and contains the residues (3359-3377) involved in the interaction with proteoglycans and the apoB/E receptor.…”