Peptide lipophilic derivatives

Although [Nle15]-gastrin-17 and [Thr,Nle]-CCK-9 are capable of binding calcium ions in TFE, they were unable to induce Ca2+ influxes into DMPC vesicles as shown in fig. 21. This fully agrees with the findings from microcalorimetric and CD measurements which excluded major interactions of these peptides with the DMPC bilayer. Conversely, the induced lipid interaction of their lipophilic derivatives DM-gastrin and DM-CCK provoked ion influxes with full equilibration... 

Several lipophilic derivatives of MDP in which the carboxyl function of the peptide chain is substituted by a L-alanyl residue esterified by a medium or long chain alcohol (68—72) have been reported 46). 

Some of their derivatives have been used as antiviral drugs. Due to their flexible chemistry, they can be exploited to design drug delivery systems and in molecular nanotechnology. In such systems, they can act as a central lipophilic core and different parts like targeting segments, linkers, spacers, or therapeutic agents can be attached to the said central nucleus. Their central core can be functionalized by peptidic and nucleic acid sequences and also by numerous important biomolecules. 

A series of amphiphiles containing a polygalactosylated tris(hydroxymethyl) aminomethane (Tris) linked to a diacyl aspartic acid (31) were synthesized by Polidori and co-workers.88 These compounds had a peptidic spacer for control of the hydrophilic/lipophilic balance as well as providing intermolecu-lar hydrogen bonding. The mono- and digalactosylated (31a, 31b) derivatives... 

H. Bundgaard, J. Mpss, Prodrugs of Peptides. 6. Bioreversible Derivatives of Thyrotropin-Releasing Hormone (TRH) with Increased Lipophilicity and Resistance to Cleavage by the TRH-Specific Serum Enzyme , Pharm. Res. 1990, 7, 885-892. 

Covalent linkage of amino acid, peptide or protein moieties onto the hydrolyzed and/or oxidized polymers (Control and Oxidized starches) was examined for its ability to improve the potential for microregion lipophilicity within the carbohydrate polymer. Proteinaceous materials are often strongly surface active (39) and may, if carefully selected, contribute positively to wall material characteristics. This selection process was carried-out using maltodextrins (DE 10 and/or 25) as the carbohydrate framework and various amino acid-derived materials as the function-altering accessory, ranging from gelatin and casein proteins to simple amino acids. 

As indicated in Table 9.1, the endocrine hormones can be divided into two major chemical classes (1) the peptides and amino acid derivatives and (2) the cholesterol-based steroid compounds. In general, the former are believed to interact primarily with membrane-associated receptors, while the latter are more lipophilic and are able to gain entrance into target cells. In any event, overactive or underactive endocrine... 

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