Structure-activity studies on the retinal rod outer segment isoprenylated protein methyltransferase
摘要:
Structure-activity studies were performed on the retinal rod outer segment isoprenylated protein methyltransferase that transfers a methyl group from S-adenosylmethionine (AdoMet) to the carboxyl group of isoprenylated (farnesylated or geranylgeranylated) cysteine residues. This methyltransferase enzyme has been shown to methylate N-acetyl-S-farnesyl-L-cysteine (L-AFC, 1) and S-(farnesyl-3-thio)propionic acid (FTP, 2). It is shown here that the enzyme does not enzymatically process D-AFC (8), although D-AFC (8) is a mixed-type inhibitor of the enzyme. Small modifications in the FTP (2) structural series generally lead to inactive substrates. For example, neither the cis- nor the trans-acrylate derivatives of FTP (2) are substrates of the enzyme, but both are inhibitors of it. Alkyl substitutions at the 3-position of FTP (2), moreover, lead to inhibitors of the methyltransferase. Substituents at the 2-position of FTP (2), as in 2-methyl-S-(farnesyl-3-thio)propionic acid (MFTP, 28) or S-farnesyl-2-(thiomethyl)acrylic acid (FTMA, 31), produce active substrates. Modifications at the carboxyl moiety produce neither substrates nor inhibitors of the enzyme. The conclusion from this and earlier studies is that the methyltransferase is selective for an isoprenylated thiopropionate moiety. Small deviations from this minimally essential structure lead to the abolition of substrate activity.
Facile triflic acid-catalyzed α-1,2-<i>cis</i>-thio glycosylations: scope and application to the synthesis of<i>S</i>-linked oligosaccharides, glycolipids, sublancin glycopeptides, and T<sub>N</sub>/T<sub>F</sub>antigens
作者:Sanyong Zhu、Ganesh Samala、Eric T. Sletten、Jennifer L. Stockdill、Hien M. Nguyen
DOI:10.1039/c9sc04079j
日期:——
access α-1,2-cis-S-linked glycosides using triflic acid as a catalyst to promote the glycosylation of a series of thiols with D-glucosamine, galactosamine, glucose, and galactose electrophiles. This method is broadly applicable for the stereoselective synthesis of S-linked glycopeptides, oligosaccharides and glycolipids in high yield and excellent α-selectivity. Many of the synthetic limitations associated
Disclosed herein are novel unsymmetrical dithiol ketals which are useful in the treatment or prevention of hypercholesterolemia, hyperlipoproteinemia, and atherosclerosis.
本文披露了一种新型的不对称二硫醇醚酮,可用于治疗或预防高胆固醇血症、高脂蛋白血症和动脉粥样硬化。
Synthesis of prenylated cysteines from serine derivatives
作者:William W. Epstein、Zhaolin Wang
DOI:10.1039/a700428a
日期:——
Prenylated cysteines are prepared by the reaction of
serineβ-lactone with prenyl thiolate.
卤代半胱氨酸是通过丝氨酸β-内酯与卤代硫酸酯反应制备的。
INHIBITORS OF POLYISOPRENYLATED METHYLATED PROTEIN METHYL ESTERASE
申请人:Lamango Nazarius Saah
公开号:US20090253640A1
公开(公告)日:2009-10-08
Inhibitors of the enzyme prenylated methylated protein methyl esterase (PMPMEase), the last step in the prenylation process for many eukaryotic proteins, having the general structure R
1
-X-A-B(R
2
)-Y or R
1
-X-A(R
2
)-B-Y, where R
1
is preferably a polyisoprenyl group, X is a linking group, Y is a group that promotes affinity interactions to the active site of PMPMEase and imparts hydrolysis resistance to the inhibitor, A and B are bridge atoms, and R
2
is a characteristic-providing substituent.
The invention relates to methods for selectively converting a cysteine residue in a peptide or protein to the dehydroalanine (Dha) residue. The method also works on selenocysteine and substituted cysteine and selenocysteine residues, resulting in the Dha residue which may be converted to any natural or unnatural amino acid residue desired without the alteration of the remainder of the peptide or protein. The invention also allows ligation of a desired peptide at any point rather than at a point where there should be a naturally occurring cysteine, thereby allowing native chemical ligation to be used in the synthesis of peptides that do not contain cysteine. The methodology allows for the synthesis of very large peptides.