Linked Life Data

6432034

Source:http://linkedlifedata.com/resource/pubmed/id/6432034

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1984-9-26
pubmed:abstractText
The rates of hydrolysis of N-[(alpha-L-rhamnopyranosyloxy)phospho]-L-leucyl-L-tryptophan (phosphoramidon), N alpha-phosphoryl-L-leucyl-L-tryptophan (PO3LeuTrp), N alpha-phosphoryl-L-leucyl-L-phenylalanine (PO3LeuPhe), and N alpha-phosphoryl-L-leucyl-L-phenylalaninamide (PO3LeuPheNH2) were followed by proton nuclear magnetic resonance spectroscopy. The rates of hydrolysis (kobsd) of PO3LeuTrp, PO3LeuPhe, and PO3LeuPheNH2 were all first order in phosphorylamide concentration over the pH range studied (3.8-9.5). The values for kobsd at pH 7.3 and 37 degrees C are as follows: PO3LeuTrp, 0.35 h-1; PO3LeuPhe, 0.63 h-1; PO3LeuPheNH2, 0.73 h-1. The values for kobsd do not significantly change between pH 5 and pH 8 but dramatically decreased with increasing pH. The hydrolysis of PO3LeuPhe and PO3LeuPheNH2 above a pH of approximately 5 was positively correlated with the concentration of monoanionic species (NHRPO3H)1-, and the values for the first-order rate constants for the respective monoanionic species were calculated to be 0.66 +/- 0.03 h-1 and 1.07 +/- 0.10 h-1. Phosphoramidon was not found to hydrolyze after 6 days at 37 degrees C at a pH of 4.6 and 7.7, while the phosphorylamide PO3LeuTrp, synthesized by the removal of L-rhamnose from phosphoramidon by base hydrolysis, was found to rapidly hydrolyze under these conditions. Solvolysis in aqueous methanol of PO3LeuPhe and PO3LeuPheNH2 indicates that the hydrolysis reaction is bimolecular, proceeding by way of direct attack of solvent (H2O, CH3OH) on phosphorus.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2766-72
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Inhibition of the elastase of Pseudomonas aeruginosa by N alpha-phosphoryl dipeptides and kinetics of spontaneous hydrolysis of the inhibitors.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't