Linked Life Data

9067256

Source:http://linkedlifedata.com/resource/pubmed/id/9067256

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1997-5-12
pubmed:abstractText
Human myeloblastin (leukocyte proteinase 3) shares many biochemical properties with leukocyte elastase, but rapidly loses enzymatic activity when raising the pH and/or the ionic strength of an acidic solution or when handled in glass vessels. This poses limits to kinetic experiments requiring long incubation times. After purification, myeloblastin was conveniently stored in a glycine/HCl buffer at pH 3.2, while assays were performed in sodium/potassium phosphate buffer at pH 7.0, ionic strength 0.11, in the presence of 0.05% w/v Triton X-100 and taking care to avoid any contact with glass surfaces. The kinetic parameters of leukocyte elastase and myeloblastin with peptide substrates, irreversible inactivators and glycosaminoglycans were compared under these conditions. MeO-succinyl-Lys(2-picolinoyl)Ala-Pro-Val-4-nitroanilide, an excellent substrate for leukocyte elastase, also proved to be a good substrate for myeloblastin (Km = 16 microM, kcat/Km = 30,600 M(-1)s(-1)). Inactivation of myeloblastin by 3,4-dichloroisocoumarin (ki/Ki = 6,389 M(-1)s(-1)) and MeO-Suc-Ala-Ala-Pro-Val-chloromethane (ki/Ki = 579 M(-1) S(-1)) occurred via a two-step, irreversible complexing mechanism with potencies one-half and one-fifth that of leukocyte elastase, respectively. Glycosaminoglycans such as chondroitin sulfate, dermatan sulfate and a chondroitin polysulfate, interacted with myeloblastin as non-essential activators in the presence of peptide substrates (activation up to a 6.7-fold factor) and as partial inhibitors (about 50% inhibition at saturation) in the presence of elastin. This property distinguishes myeloblastin from leukocyte elastase, which is always inhibited by glycosaminoglycans, independently of the substrate.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1431-6730
pubmed:author
pubmed:issnType
Print
pubmed:volume
377
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
579-86
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Human myeloblastin (leukocyte proteinase 3): reactions with substrates, inactivators and activators in comparison with leukocyte elastase.
pubmed:affiliation
University Hospital, Department of Rheumatology, Zurich, Switzerland.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't