Linked Life Data

2139028

Source:http://linkedlifedata.com/resource/pubmed/id/2139028

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1990-5-24
pubmed:abstractText
The lysosomal hydrolase beta-hexosaminidase (beta-N-acetylhexosaminidase, EC 3.2.1.52) exists as two major isozymes in normal human tissue: an acidic A-form and a basic B-form. There are also minor forms of intermediate pI known as I-forms. Increases in one or more of these intermediates have been associated with various disease states. Although the two major isozymes have been extensively studied, the structure and biosynthetic origins of the I-forms are unknown. Characterization of a placental hexosaminidase I-form, presented in this report, demonstrates that it is composed of two forms of partially processed hexosaminidase A. The major form contains an intact pro-alpha chain and a pro-beta chain lacking 2 residues from its amino terminus (Ala and Arg). The minor form also contains an alpha and a beta subunit, but each has undergone further proteolytic processing. The amino terminus of each of these partially processed polypeptide chains matches one of those previously found on stable processing intermediates in a single normal human fibroblast cell line. These data confirm that similar processing intermediates exist in human placenta, suggesting that this I-form lacks a unique enzymatic function in vivo. A sequence of normal proteolytic processing events is postulated.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
265
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6794-9
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Characterization of human placental beta-hexosaminidase I2. Proteolytic processing intermediates of hexosaminidase A.
pubmed:affiliation
Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't