The number of ion channels expressed on the cell surface shapes the complex electrical response of excitable cells. An imbalance in the ratio of inward and outward conducting channels is unfavorable and often detrimental. For example, over- or underexpression of voltage-gated K(+) (Kv) channels can be cytotoxic and in some cases lead to disease. In this study, we demonstrated a novel role for S...

Fucosylated chondroitin sulfate (FuCS), a kind of complex glycosaminoglycan from sea cucumber, has potent anticoagulant activity. In order to understand the relationship between structures and activity, the depolymerized FuCS (dFuCS) was chosen to prepare its derivates by selective substitution at OH groups. Its O-acylation was carried out in a homogeneous way using carboxylic acid anhydrides. ...

The Ras family of GTPases are important in cell signaling and frequently mutated in human tumors. Understanding their regulation is thus important for studying biology and human diseases. Here, we report that a novel posttranslational mechanism, reversible lysine fatty acylation, regulates R-Ras2, a member of the Ras family. SIRT6, a sirtuin with established tumor suppressor function, regulates...

3-Phenylbenzofuranone (l), when deprotonated with sodium hydride and treated with excess chloroformates, generally affords products arising from oxygen acylation (enol carbonates 4). Such molecules, when treated with a catalytic quantity of 4-(dimethy1amino)pyridine (DMAP, 6) in halogenated solvents, rearrange to the carbon-acylated isomers 3. These migrations are proposed to involve the interm...

S-acylation, the attachment of fatty acids onto cysteine residues, regulates protein trafficking and function and is mediated by a family of zDHHC enzymes. The S-acylation of peripheral membrane proteins has been proposed to occur at the Golgi, catalyzed by an S-acylation machinery that displays little substrate specificity. To advance understanding of how S-acylation of peripheral membrane pro...

12 Ras proteins play vital roles in numerous biological processes and Ras mutations are found in many 13 human tumors. Understanding how Ras proteins are regulated is important for elucidating cell signaling 14 pathways and identifying new targets for treating human diseases. Here we report that one of the K-Ras 15 splice variants, K-Ras4a, is subject to lysine fatty acylation, a previously und...

The kinetics of the acylation of alpha-chymotrypsin by a series of substituted phenyl p-nitrobenzoates have been studied by stopped flow and conventional spectrophotometry. Electron withdrawal in the leaving group accelerates the rate of acylation, and the p value obtained for eight esters is +1.96. The pH- and pD-independent acylation rate constants are, respectively, 1.40 X 10(4) M-1S-1 and 1...

12 The selective acylation of multifunctional compounds exhibiting both alcohol and amino 13 groups gives interesting products with many applications in food, cosmetic and 14 pharmaceutical industries, but it is real challenge. The current work describes the different 15 behavior shown by Candida antarctica lipase B (Novozym 435) when catalyzing the O-16 acylation and N-acylation of bifunctiona...

The N-acylation of ethanolamine (2) with various fatty acids 1a-d and esters of fatty acids 1e-h using Candida antarctica B lipase (Novozym((R)) 435) are described and optimum conditions for selective N-acylation rather than O-acylation are also discussed. Microwave assisted solution phase, solid supported and conventional methods were investigated and results were compared. There is a synergy ...

A variety of cysteine-containing, lipid-modified peptides are found to be S-acylated by cultured mammalian cells. The acylation reaction is highly specific for cysteinyl over serinyl residues and for lipid-modified peptides over hydrophilic peptides. The S-acylation process appears by various criteria to be enzymatic and resembles the S-acylation of plasma membrane-associated proteins in variou...