Search results for "Molecular sequence"

Complete cDNA sequence coding for the MHC class II RT1.B alpha chain of the Lewis rat.

1989

Synthesis of glycopeptides and neoglycoproteins containing the fucosylated linkage region of N-glycoproteins.

1994

Abstract N-Glycoproteins fucosylated in the core region occur in tumor membranes and virus envelopes. Partial structures of such N-glycoproteins containing fucosylated chitobiosyl asparagine conjugates were synthesized using the allyloxycarbonyl (Aloc) and the tert-butyl ester protecting groups in the peptide portion. As the α-fucosidic bond of the conjugates revealed to be very sensitive to acids when carrying ether-type protecting groups, a method for exchanging the protecting groups of the fucose portion of saccharides was developed. Conjugates containing O-acetyl protected fucose proved to be stable against acids used in glycopeptide syntheses. These methods were applied in the synthesi…

Transient structural ordering of the RNA-binding domain of carnation mottle virus p7 movement protein modulates nucleic acid binding.

2005

Plant viral movement proteins bind to RNA and participate in the intra- and intercellular movement of the RNAs from plant viruses. However, the role and magnitude of the conformational changes associated with the formation of RNA-protein complexes are not yet defined. Here we describe studies on the relevance of a preexisting nascent alpha-helix at the C terminus of the RNA-binding domain of p7, a movement protein from carnation mottle virus, to RNA binding. Synthetic peptide analogues and single amino acid mutation at the RNA-binding domain of recombinant p7 protein were used to correlate the transient structural order in aqueous solution with RNA-binding potential.

Chemoenzymatic synthesis of O-glycopeptides carrying the tumor associated TN-antigen structure

1993

Abstract The application of the lipase-catalyzed C-terminal deprotection of heptyl esters for the construction of acid- and base-labile O -glycopeptides carrying the characteristic structural element of the tumor associated T N -antigen (GalNAc α→Ser/Thr) is described

SELF-ASSEMBLED AMPHIPHILIC HYALURONIC ACID GRAFT COPOLYMERS FOR TARGETED RELEASE OF ANTITUMORAL DRUG

2009

Polymeric micelles obtained by self-assembling of amphiphilic hyaluronic acid (HA) graft copolymers have been prepared and characterized. In particular, hyaluronic acid (HA) has been grafted to polylactic acid (PLA) and polyethylenglycol chains (PEG), then the copolymers able to form micelles in aqueous medium have been chosen to entrap the antitumoral drug Doxorubicin. The critical aggregation concentration of HA-g-PLA or HA-g-PLA-g-PEG micelles has been determined by using pyrene as a fluorescent probe, whereas their shape and size have been evaluated by light scattering measurements, scanning and transmission electron microscopies. The selective cytotoxicity of drug loaded micelles towar…

Two new biologically active triterpene saponins from Acanthophyllum squarrosum.

2000

Two novel triterpenoid saponins (1 and 2) have been isolated from the roots of Acanthophyllum squarrosum. The structures were established mainly by a combination of 2D NMR techniques as 3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-be ta-D-glucuronopyranosylgypsogenin-28-O-beta-D-xylopyranosyl-(1-->3 )-b eta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->4)-[alpha-L- rhamnopyranosyl-(1-->3)]-beta-D-fucopyranoside (1) and 3-O-beta-D-glucopyranosylgypsogenin-28-O-alpha-L-rhamnopyranosyl-( 1-- >2)-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->6 )]- beta-D-glucopyranoside (2). Compound 1 showed a moderate concentration-dependent immunomodulatory effect …

Dynamics of the biosynthesis of methylursubin in plant cells employing in vivo 13CNMR without labelling.

1995

Abstract In vivo NMR experiments with a digital 600 MHz instrument, exploiting the natural abundance of 13C, allowed us for the first time to follow the biosynthesis of the newly detected glycoside, methylursubin ( 4- methoxyphenyl -O-β- d -primeveroside ), from 4-methoxyphenol through the intermediate methylarbutin in cell suspensions of the Indian medical plant, Rauwolfia serpentina. The metabolic dynamics indicate that, within 48 hr, 4-methoxyphenol is almost completely converted into the primeveroside, methylursubin. Because of the higher sensitivity at 150.9 MHz compared to that at 100.6 MHz, measuring times could be reduced to 1.5 hr. This allows detailed monitoring of the conversion …

Acylated triterpene saponins from Silene jenisseensis

1995

Abstract From the roots of Silene jenisseensis a new trans-p-methoxycinnamoyl triterpene saponin has been isolated along with its cis-p-methoxycinnamoyl isomer as an inseparable mixture. Their structures were established by chemical means and spectroscopic methods including 1D- and 2D-homonuclear and heteronuclear correlation NMR spectroscopy as 3-O-[β- d -galactopyranosyl -(1 → 2)-β- d -glucuronopyranosyl ]-28-O-[β- d -glucopyranosyl -(1 → 2)-α- l - rhamnopyranosyl -(1 → 2)-β- d -4-O-trans-p- methoxycinnamoyl-fucopyranosyl ] quillaic acid and its cis-isomer, respectively. They did not show any activity in the in vitro chemoluminescence granulocytes assay, but exhibited only a weak inhibito…

A new biologically active acylated triterpene saponin from Silene fortunei.

1998

A new acylated triterpene-saponin (1), together with a mixture of the known jenisseensosides C and D, has been isolated from the roots of Silene fortunei. The structure of the new compound was established by chemical means and spectroscopic methods as 3-O-[beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl]-28 -O- [[alpha-L-arabinopyranosyl-(1-->2)-alpha-L-arabinopyranosyl- (1-->3)-b eta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)]-[beta-D- glucopyranosyl-(1-->3)]-4-O-acetyl-beta-D-fucopyranosyl]quillaic acid. This saponin showed a significant enhancement of granulocyte phagocytosis in vitro.

Three new acylated triterpene saponins from Acanthophyllum squarrosum.

2001

Three new triterpenoid saponins, 1-3, were isolated from the roots of Acanthophyllum squarrosum. Their structures were established mainly by 2D NMR techniques as 3-O-beta-D-galactopyranosyl-(1--2)-[beta-D-xylopyranosyl-(1--3)]-beta-D-glucuronopyranosyl-gypsogenin-28-O-beta-D-xylopyranosyl-(1--3)-beta-D-xylopyranosyl-(1--4)-beta-D-xylopyranosyl-(1--4)-3-O-acetyl-alpha-L-rhamnopyranosyl-(1--2)-3,4-di-O-acetyl-beta-D-fucopyranoside (1), 3-O-beta-D-galactopyranosyl-(1--2)-[beta-D-xylopyranosyl-(1--3)]-beta-D-glucuronopyranosyl-gypsogenin-28-O-beta-D-xylopyranosyl-(1--4)-alpha-L-rhamnopyranosyl-(1--2)-[5-O-acetyl-alpha-L-arabinofuranosyl-(1--3)]-4-O-acetyl-beta-D-fucopyranoside (2), and 3-O-beta…