Linked Life Data

16117548

Source:http://linkedlifedata.com/resource/pubmed/id/16117548

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
34
pubmed:dateCreated
2005-8-24
pubmed:abstractText
Various amino acid-carrying amphiphiles were synthesized, and the pK values of the attached amino acid residues were investigated at the air-water interface and in aqueous vesicles using pi-A isotherm measurements, (1)H NMR titration, and IR spectroscopy in reflection-adsorption mode. The epsilon-amino group of the Lys residue embedded at the air-water interface displays a significant pK shift (4 or 5 unit) compared with that observed in bulk water, while the pK shift in aqueous vesicles was not prominent (ca. 1 unit). Moreover, pK values of the amino acids at the air-water interface can be tuned simply by control of the subphase ionic strength as well as by molecular design of the amphiphiles. A simple equation based on the dominant contribution by the electrostatic energy to the pK shift reproduces well the surface pressure difference between protonated and unprotonated species, suggesting a reduction in the apparent dielectric constant at the air-water interface. Hydrolysis of a p-nitrophenyl ester derivative was used as a model reaction to demonstrate the use of the Lys-functionalized monolayer. Efficient hydrolysis was observed, even at neutral pH, after tuning of pK for the Lys residue in the monolayer, which is a similar case to that occurring in biological catalysis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0002-7863
pubmed:author
pubmed:issnType
Print
pubmed:day
31
pubmed:volume
127
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12074-80
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Tunable pK of amino acid residues at the air-water interface gives an L-zyme (langmuir enzyme).
pubmed:affiliation
Supermolecules Group, Advanced Materials Laboratory, National Institute for Materials Science (NINS), 1-1 Namiki, Tsukuba 305-0044, Japan. ARIGA.Katsuhiko@nims.go.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't