Search results for " AMINO"

Single cigar-shaped nanopores functionalized with amphoteric amino acid chains: experimental and theoretical characterization.

2012

We present an experimental and theoretical characterization of single cigar-shaped nanopores with pH-responsive carboxylic acid and lysine chains functionalized on the pore surface. The nanopore characterization includes (i) optical images of the nanostructure obtained by FESEM; (ii) different chemical procedures for the nanopore preparation (etching time and functionalizations; pH and electrolyte concentration of the external solution) allowing externally tunable nanopore responses monitored by the current-voltage (I-V) curves; and (iii) transport simulations obtained with a multilayer nanopore model. We show that a single, approximately symmetric nanopore can be operated as a reconfigurab…

Population genetics of cucumber mosaic virus infecting medicinal, aromatic and ornamental plants from northern Italy

2012

An epidemiological survey carried at the Herb Garden of Casola Valsenio (Emilia Romagna region; Northern Italy) from 2006 to 2009 resulted in finding Cucumber mosaic virus (CMV) as the infectious agent of several ornamental, medicinal and aromatic plants. All CMV-infected plant species showed leaf symptoms followed, in some cases, by flower colour-breaking and stunting. Genetic analysis consisted in the characterization of movement protein gene of each CMV-isolate by single strand polymorphism analysis and sequencing. Phylogenetic trees identified only two isolates as member of subgroup II, while all other isolates were part of subgroup IA. This survey confirms an unexpected increment of CM…

Determination of total free amino acids with o-phthalaldehyde and N-acetyl-l-cysteine

1990

Abstract A spectrophotometric procedure is proposed for the determination of total free amino acids after reaction with o-phthalaldehyde and N-acetyl- l -cysteine, using isoleucine as the reference. The procedure was applied to the analysis of five samples of widely different composition. Recoveries were 98–105%.

Screening contact allergens from cosmetics using an optical biosensor

2006

Composizione aminoacidica degli occhi di piccoli pesci pelagici in relazione ai processi oceanografici negli habitat di deposizione

Studio della valutare della composizione aminoacidica degli occhi di piccoli pesci pelagici in relazione ai processi oceanografici negli habitat di deposizione. La scelta di proporre uno studio sulla composizione aminoacidica degli occhi di E. encrasicolus è stata suggerita da studi pregressi che ne hanno evidenziato la specificità alla specie. In particolare, le misurazioni morfometriche e le analisi della composizione aminoacidica (AAC), degli enzimi, dei lipidi e carboidrati effettuati sulle larve di acciuga, hanno permesso di valutare se le diverse caratteristiche ambientali delle due aree possono influenzare le larve di Engraulis encrasicolus all’interno del Canale di Sicilia. Si tratt…

Rat olfactory bulb and epithelium UDP-glucuronosyltransferase 2A1 (UGT2A1) expression: in situ mRNA localization and quantitative analysis.

2001

UDP-glucuronosyltransferases (UGTs) form a multigenic family of enzymes involved in the biotransformation and elimination of numerous endo- and xenobiotic compounds. Beside the diverse UGT isoforms present in the liver as well as in other tissues, the UGT2A1 isoform, also called olfactory UGT, was initially thought to be expressed in the nasal epithelium only. In this work, we demonstrate the UGT2A1 mRNA expression in the olfactory bulb, using in situ hybridization and quantitative reverse transcription-polymerase chain reaction (RT-PCR) techniques. Within the epithelium, UGT2A1 mRNA is mainly found in the sustentacular cells and to a lesser extent in Bowman's gland cells. Moreover, in situ…

Cloning of branched chain amino acid biosynthesis genes and assays of alpha-acetolactate synthase activities in Leuconostoc mesenteroides subsp. crem…

1999

Abstract A genomic library from Leuconostoc mesenteroides subsp. cremoris (Lmc) in Escherichia coli was screened for α-acetolactate synthase (ALS) activity using a phenotypic test detecting the production of acetolactate or related C 4 derivatives (diacetyl, acetoin or 2,3-butanediol) in the culture. Four recombinant E. coli clones, with plasmids containing overlapping DNA fragments and displaying anabolic ALS activity, were selected. This activity is encoded by an ilvB gene belonging to a putative operon which contains genes highly similar to the genes of the branched chain amino acid (BCAA) operon of Lactococcus lactis subsp. lactis. This putative BCAA operon is not functional as the ilvA…

Discovery and molecular characterization of a plasmid localized in Buchnera sp. bacterial endosymbiont of the aphid Rhopalosiphum padi

1995

We have identified and completely sequenced a novel plasmid isolated from the aphid Rhopalosiphum padi. Evidence which suggests that the plasmid occurs localized within the bacterial endosymbionts is presented. The plasmid contains the four genes that constitute the entire leucine operon. This fact makes it really unique since most plasmids are dispensable and lack genes that encode essential anabolic functions. Four more phloem-feeding aphid species also seem to contain homologous plasmids. Although further work is necessary, we hypothesize that this plasmid has appeared during the evolution of the symbiotic association between the aphid and the bacterial endosymbiont. The fact that this p…

Tonoplast intrinsic proteins from cauliflower (Brassica oleracea L. var. botrytis): immunological analysis, cDNA cloning and evidence for expression …

1998

The vacuolar membrane (tonoplast) of plant cells contains aquaporins, protein channels that facilitate the selective transport of water. These tonoplast intrinsic proteins (TIPs) of 23-29 kDa belong to the ancient major intrinsic protein (MIP) family. A monospecific polyclonal antiserum directed against a 26 kDa intrinsic protein from the tonoplast of meristematic cells from cauliflower (Brassica oleracea L. var. botrytis) was used to screen a cDNA library. Two distinct cDNAs have been isolated. Both clones, c26-1 and c26-2, encode closely related TIPs. The c26-1 insert, consisting of 933 bp upstream of the poly(A) tail, is a full-length cDNA with an open reading frame encoding a protein of…

Fast and Efficient Microwave-Assisted Synthesis of Perylenebisimides

2015

Perylene-3,4,9,10-tetracarboxylic acid bisimides have been widely studied as industrial pigments. Lately, these dyes have drawn considerable attention because of applications as photocatalysts and organic semi-conductors. Here, we report a novel method for fast and efficient synthesis of many different perylenebisimides, based on microwave-assisted reactions.