Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2007-2-22
pubmed:abstractText
Ceramidases (CDases) hydrolyze ceramide to sphingosine (SPH) and fatty acid. Pseudomonas CDase (pCDase) is a homolog of mammalian neutral ceramidases and may play roles in disease pathogenesis. In this study, pCDase was cloned and expressed in Escherichia coli (E. coli). The expressed recombinant pCDase was solubilized by optimizing several factors, including culture medium, the concentration of isopropyl-beta-thiogalactopyranoside (IPTG), temperature, and time of induction, which were identified to be critical for the optimal production of recombinant pCDase. The recombinant pCDase was purified using nickel-nitrilotriacetic acid affinity, phenyl-Sepharose, and Q-Sepharose column chromatography, which gave an overall yield of 0.45 mg/l purified protein of starting culture. The activity of the recombinant pCDase followed classical Michaelis-Menten kinetics, with optimum activity in the neutral pH range. Both the hydrolytic and the reverse activities of CDase were stimulated by calcium with an affinity constant (K(a)) of 1.5 microM. Kinetics studies showed that calcium caused a decrease of K(m) and an increase in V(max) of pCDase. Calcium and D-erythro-sphingosine caused significant changes in the near ultraviolet circular dichroism (CD) spectra and the changes were inhibited in the presence of EGTA. These results identify important interactions between calcium and pCDase, which may play an essential role in the interaction of pCDase and its substrate.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-2275
pubmed:author
pubmed:issnType
Print
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
600-8
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Large-scale purification and characterization of recombinant Pseudomonas ceramidase: regulation by calcium.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural