Linked Life Data

6378189

Source:http://linkedlifedata.com/resource/pubmed/id/6378189

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1984-8-15
pubmed:abstractText
The catalytic-site thiol groups of papain (EC 3.4.22.2) and actinidin (EC 3.4.22.14) were each labelled with the nitrobenzofurazan (Nbf) chromophore by reaction with 4-chloro-7-nitrobenzofurazan at pH 4.4. The electronic-absorption spectra of both labelled enzymes were determined in aqueous solution, in the pH ranges approx. 2-5 for S-Nbf-papain and approx. 3.3-8 for S-Nbf-actinidin, and for the latter also in 6 M-guanidinium chloride. The spectrum of S-Nbf-papain is characterized by lambda max. = 402 nm at pH 5 and by lambda max. = 422 nm at pH 2.18. The pH-dependent shift in lambda max. accompanies a pH-dependent change in A 430, the nature of which is consistent with its dependence on a single ionizing group with pKa 3.7. The spectrum of S-Nbf-actinidin is pH-independent in the pH range approx. 3.3-8 and is characterized by lambda max. = 413 nm. This absorption maximum shifts to 425 nm in 6M-guanidinium chloride. These results are discussed and related to those reported previously from studies on papain and actinidin with various reactivity probes. Despite the close similarity in the catalytic sites of papain and actinidin deduced from X-ray-diffraction studies, the considerable differences in their reactivity characteristics are mirrored by differences in their electric fields detected by the Nbf spectroscopic label. The microenvironment in the catalytic site of actinidin appears to favour the existence of ions significantly more than in the corresponding region in papain.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/6378189-11778, http://linkedlifedata.com/resource/pubmed/commentcorrection/6378189-17393, http://linkedlifedata.com/resource/pubmed/commentcorrection/6378189-435250, http://linkedlifedata.com/resource/pubmed/commentcorrection/6378189-4748829, http://linkedlifedata.com/resource/pubmed/commentcorrection/6378189-4946704, http://linkedlifedata.com/resource/pubmed/commentcorrection/6378189-5506167, http://linkedlifedata.com/resource/pubmed/commentcorrection/6378189-592367, http://linkedlifedata.com/resource/pubmed/commentcorrection/6378189-6311173, http://linkedlifedata.com/resource/pubmed/commentcorrection/6378189-6347181, http://linkedlifedata.com/resource/pubmed/commentcorrection/6378189-6758764, http://linkedlifedata.com/resource/pubmed/commentcorrection/6378189-7003158, http://linkedlifedata.com/resource/pubmed/commentcorrection/6378189-7025834, http://linkedlifedata.com/resource/pubmed/commentcorrection/6378189-7034724, http://linkedlifedata.com/resource/pubmed/commentcorrection/6378189-949979, http://linkedlifedata.com/resource/pubmed/commentcorrection/6378189-952885
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0264-6021
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
220
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
609-12
pubmed:dateRevised
2010-9-13
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Differences between the electric fields of the catalytic sites of papain and actinidin detected by using the thiol-located nitrobenzofurazan label as a spectroscopic reporter group.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't