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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2000-12-20
pubmed:abstractText
Numerous respiratory bovine coronaviruses (RBCV) were isolated recently from nasal swab samples and lung tissues of feedlot cattle with acute respiratory tract disease. These newly emerging RBCV isolates exhibited distinct phenotypic features that differentiated them from enteropathogenic bovine coronaviruses (EBCV). The RBCV strains had a receptor-destroying enzyme function mediated by acetylesterase (AE) activity of the haemagglutinin-esterase (HE) glycoprotein. The HE genes of wild-type EBCV strain LY138 and RBCV strains OK-0514 (OK) and LSU-94LSS-051 (LSU) were cloned, sequenced and transiently expressed in COS-7 cells. The enzymic properties of HE proteins in COS-7 cellular extracts and in purified virus preparations were assayed at room temperature, 37 degrees C and 39 degrees C by two different assays. One assay used p-nitrophenyl acetate (PNPA) as substrate and detected serine-esterase activity; the second assay monitored AE function with bovine submaxillary mucin (BSM) as substrate. The PNPA tests confirmed that HE proteins of EBCV and RBCV were functionally expressed in transfected COS-7 cells. Time-dependent determination of the AE activity of purified RBCV OK and LSU particles showed lower AE activity at 39 degrees C than at 37 degrees C, whereas the purified EBCV LY particles retained full AE activity at both 37 degrees C and 39 degrees C. Transiently expressed RBCV HE exhibited a marked reduction of AE activity after 40 min of assay time at 37 degrees C. In contrast, the AE activity of the transiently expressed EBCV HE remained stable beyond 40 min. The deduced amino-acid sequences of the HE proteins specified by the RBCV strains OK and LSU contained specific amino-acid changes in comparison with the EBCV LY strain, which may be responsible for the observed enzymic differences. These results are consistent with the hypothesis that RBCV strains have evolved to selectivelyreplicate in respiratory tissues and that HE may play a role in this tissue tropism.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-2615
pubmed:author
pubmed:issnType
Print
pubmed:volume
49
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1119-27
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11129725-Acetates, pubmed-meshheading:11129725-Acetylesterase, pubmed-meshheading:11129725-Amino Acid Sequence, pubmed-meshheading:11129725-Animals, pubmed-meshheading:11129725-COS Cells, pubmed-meshheading:11129725-Cattle, pubmed-meshheading:11129725-Cattle Diseases, pubmed-meshheading:11129725-Cloning, Molecular, pubmed-meshheading:11129725-Coronavirus, Bovine, pubmed-meshheading:11129725-Coronavirus Infections, pubmed-meshheading:11129725-Esterases, pubmed-meshheading:11129725-Hemagglutinins, Viral, pubmed-meshheading:11129725-Mucins, pubmed-meshheading:11129725-Nitrophenols, pubmed-meshheading:11129725-Respiratory Tract Infections, pubmed-meshheading:11129725-Sequence Analysis, DNA, pubmed-meshheading:11129725-Submandibular Gland, pubmed-meshheading:11129725-Temperature, pubmed-meshheading:11129725-Transfection, pubmed-meshheading:11129725-Viral Fusion Proteins
pubmed:year
2000
pubmed:articleTitle
Temperature-sensitive acetylesterase activity of haemagglutinin-esterase specified by respiratory bovine coronaviruses.
pubmed:affiliation
Department of Veterinary Microbiology and Parasitology, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't