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E L Chaikof

Publications and source records attributed to E L Chaikof.

59 records · Page 4Linked to original sources

A convenient route to thiol terminated peptides for conjugation and surface functionalization strategies.

The derivatization of poly(p-(chloromethyl)styrene-co-divinylbenzene) (Merrifield resin) with N-(tert-butoxycarbonyl)-2-aminoethanethiol is presented as a convenient route for the generation of thiol terminated peptides using a solid phase methodology. Maximum resin substitution reached 92% (773 mumol/g) after 24 h. However, at 30 min, yields exceeded 400 mumol/g, above which the resin is suitable for solid phase peptide synthesis. Thiol terminated peptides are well-suited for subsequent chemical conjugation reactions or for the formation of organic monolayers on metal substrates.

Amino Acid Sequence↗

Synthesis and terminal functionalization of a polymerizable phosphatidylethanolamine.

We report the design and synthesis of bifunctional phospholipid conjugates, which contain a polymerizable acrylate group and a terminal linker, such as biotin or N-(epsilon-maleimidocaproyl (EMC), to facilitate bioconjugation reactions. The lipid conjugate can be used to generate a multifunctional substrate-supported phospholipid film that is further stabilized via in-situ photocopolymerization.

Acrylates↗

Neoglycophospholipids with alkyl spacers: synthesis via an improved reductive amination and monolayer properties.

An efficient synthesis of neoglycophospholipids with variable length alkyl spacer chains is described. Neoglycophospholipids tethered by alkyl chains of 3, 5, 7, 10, and 16 methylene units were synthesized in good overall yields in four steps. The key intermediates, omega-oxoalkyl glycopyranosides, were synthesized in two steps by glycosidation of chloro (or ethylthio) glycosides with a diol followed by oxidation of the remaining hydroxy group to an aldehyde functionality. Conjugation of the omega-glycoalkyl aldehyde with distearoylphosphatidylethanolamine via an improved reductive amination procedure significantly enhanced efficiency and yields with respect to those from traditional procedures. The amphiphilic properties of the neoglycophospholipids were characterized at the air-water interface. While the carbohydrate head group had relatively little effect, the length of the alkyl spacer profoundly influenced surface area-pressure isotherms.

Amines↗

Alpha4beta1 and alpha5beta1 control cell migration on fibronectin by differentially regulating cell speed and motile cell phenotype.

Computer-aided time lapse fluorescence videomicroscopy was used to study single cell migration behavior of human aortic endothelial cells on fibronectin coated substrates of varying protein surface density. The role of receptors alpha5beta1, alpha(v)beta3, and alpha4beta1 in mediating cell adhesion and migration on fibronectin was characterized using integrin specific monoclonal antibodies. Matrix density had a direct effect on controlling the proportion of migrating cells and the directional persistence of cell movement (p<0.01). While there was relatively little influence of fibronectin surface density on absolute migration speed, the ability of endothelial cells to disperse over a surface, as measured by the dispersion coefficient, was biphasic with respect to the surface density of this matrix protein (p<0.005). Both cell speed and the proportion of migrating cells was controlled by alpha4beta1 (p<0.01). However, alpha5beta1 selectively regulated the transformation of stationary cells to those exhibiting motile behavior (p<0.05). Migratory responses on fibronectin were not influenced by blockade of the alpha(v)beta3 receptor. It is noteworthy that cell surface adhesive receptors which control commitment to a motile phenotype are not necessarily the same as those that control migration speed.

Antibodies, Monoclonal↗