Linked Life Data

18247596

Source:http://linkedlifedata.com/resource/pubmed/id/18247596

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2008-2-14
pubmed:abstractText
The kinetics of proton exchange between dormant spores and aqueous environment was examined by time-resolved micropotentiometry, the method we recently introduced for hydrogel particles of micro- and nanometer diameter (J. Phys. Chem. B 2006, 110, 15107). In this work, the method was applied to the suspensions of dormant Bacillus subtilis spore of different concentrations to show that proton uptake kinetics was a multistep process involving a number of successively approximately 10-fold slower steps of proton penetration into the bulk and their binding to the ionizable groups within different layers of a spore structure. By analyzing the proton equilibrium binding to ionizable groups inside a spore, it was shown that each Bacillus subtilis spore behaves like almost infinite ionic reservoir capable of accumulating billions of protons (N approximately 2 x 10(10) per spore). The obtained pK(a) value of 4.7 for the spores studied is the first quantitative indication on carboxyl groups as the major ionizable groups fixed in a spore matrix. In general, proton equilibrium binding within the spore matrix obeys the fundamental law of the Langmuir isotherm. The proton binding to the ionizable groups slows down the free proton diffusion within a spore, but this effect is substantially weakened by increasing the initial concentration of protons added. On the basis of the diffusion time analysis, it was found that the effective diffusion coefficient for hydrogen ions within the spore core can be up to 3 orders of magnitude lower than that within the coats and cortex. We speculate that the spore inner membrane which separates core from cortex and coats in a dormant spore is a major permeability barrier for protons to penetrate into a lockbox of the genetic information (core).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1520-6106
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
112
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2233-44
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Physicochemical characterization of natural ionic Microreservoirs: Bacillus subtilis dormant spores.
pubmed:affiliation
Department of Chemistry and Physical Sciences, Pace University, 861 Bedford Road, Pleasantville, New York 10570, USA. skazakov@pace.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't