The product specificity and pH optimum of the thermostable cyclodextrin glycosyltransferase (CGTase) from Thermoanaerobacterium thermosulfurigenes EM1 was engineered using a combination of x-ray crystallography and site-directed mutagenesis. Previously, a crystal soaking experiment with the Bacillus circulans strain 251 beta-CGTase had revealed a maltononaose inhibitor bound to the enzyme in an...

The molecular recognition behaviors of some representative bile salts by three 3,6'-bridged beta-cyclodextrin dimers with oligo(ethylenediamino) linkers in different lengths, i.e. 3,6'-(ethylenediamino-bridged) beta-cyclodextrin dimer (1), 3,6'-(diethylenetriamino-bridged) beta-cyclodextrin dimer (2), and 3,6'-(triethylenetetraamino-bridged) beta-cyclodextrin dimer (3), were investigated in aqu...

BACKGROUND Nowadays, the encapsulation of cytotoxic chemotherapeutic agents is attracting interest as a method for drug delivery. We hypothesized that the efficiency of helenalin might be maximized by encapsulation in β-cyclodextrin nanoparticles. Helenalin, with a hydrophobic structure obtained from flowers of Arnica chamissonis and Arnica Montana, has anti-cancer and anti-inflammatory activit...

The purpose of this work is to investigate the inclusion complexation between a novel amphiphilic biotransesterified cyclodextrin (CD), incorporated in nanostructured environment, and a model drug compound. A water-insoluble γ-cyclodextrin derivative (γ-CD-C10), polysubstituted with multiple (n=7-8) decanoyl chains (C10) on the secondary face, is produced by enzymatically-assisted esterificatio...

A series of cyclodextrin-cinchona alkaloid inclusion complexes were prepared from beta-cyclodextrin, heptakis(2,6-di-O-methyl)-beta-cyclodextrin and heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin and four cinchona alkaloids in ca. 90% yields, and their inclusion complexation behavior was investigated at pH 7.2 and 1.5 by means of fluorescence, UV/Vis and 2D NMR spectroscopy. The results showed ...

Unfolding/refolding of a plasma protein, human serum albumin (HSA), is studied using fluorescence correlation spectroscopy (FCS) and single molecule fluorescence resonance energy transfer (sm-FRET). Addition of cholesterol causes unfolding of HSA resulting in an increase in the hydrodynamic diameter (dH = 2rH) from 76 Å in the native state to 120 Å upon addition of 1 mM cholesterol. Addition of...

Internalization of some plasma membrane constituents, bacterial toxins, and viruses occurs via caveolae; however, the factors that regulate caveolar internalization are still unclear. Here, we demonstrate that a brief treatment of cultured cells with natural or synthetic glycosphingolipids (GSLs) or elevation of cholesterol (either by acute treatment with mbeta-cyclodextrin/cholesterol or by al...

Bacillus licheniformis RM44 was isolated from hot spring near Karachi and screened forthe production of extracellular amylase Amy RM44. Amy RM44 was purified to homogeneityon a single step by affinity chromatography using insoluble corn starch. The molecular weightof Amy RM44 was estimated to be 66 kDa by SDS–PAGE and zymographic analysis. Nine foldpurification was achieved with the specific ac...

the purpose of this study was to prepare and characterize microspheres loaded by cyclosporine a(cya)-cyclodextrin (cd) complex. to achieve this goal, plga microspheres loaded by cya cd complex were prepared by multiple emulsificationsolvent evaporation methods.morphology, size, encapsulation efficiency and drug release from these microspheres were evaluated. microscopic evaluation of microspher...

Piroxicam-beta-cyclodextrin is a complex of the established nonsteroidal antiinflammatory drug (NSAID) piroxicam and an inert cyclic macromolecule, beta-cyclodextrin. In clinical trials in patients with rheumatic diseases or pain arising from other conditions, it was as effective an analgesic as standard piroxicam, and showed a faster onset of action on the first day of treatment. In short term...