Linked Life Data

19751975

Source:http://linkedlifedata.com/resource/pubmed/id/19751975

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
20
pubmed:dateCreated
2009-9-28
pubmed:abstractText
The enzymatic activities of carbonic anhydrase (CA, EC 4.2.1.1) isozymes CA I, II, IX (catalytic domain (cdCA IX) and catalytic domain plus proteoglycan, flCA IX), XII and XIV were investigated as a function of pH for the CO2 hydration to bicarbonate and a proton. The cytosolic isoforms CA I and II as well as the catalytic domain of CA IX, together with the transmembrane isoforms CA XII and XIV showed sigmoid pH dependencies of k(cat)/KM, with a pKa of 6.90-7.10, showing thus optimal catalytic efficiency around pH 7. The full length CA IX had a similar shape of the pH dependency curve but with a pKa of 6.49, having thus maximal catalytic activity at pH values around 6.5, typical of hypoxic solid tumors in which CA IX is overexpressed. The proteoglycan domain of CA IX (present only in this transmembrane isoform) may thus act as an intrinsic buffer promoting efficient CO2 hydration at acidic pH values found in hypoxic tumors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1464-3405
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5825-8
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
The proteoglycan region of the tumor-associated carbonic anhydrase isoform IX acts as anintrinsic buffer optimizing CO2 hydration at acidic pH values characteristic of solid tumors.
pubmed:affiliation
Universita degli Studi di Firenze, Laboratorio di Chimica Bioinorganica, Rm. 188, Via della, Lastruccia 3, I-50019, Sesto Fiorentino (Firenze), Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't