Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Disseminated Mycobacterium avium-Mycobacterium intracellulare (M. avium complex) disease is a prevalent opportunistic infection in patients with acquired immune deficiency syndrome. Because of the increasing importance of this disease, an M. avium complex lambda gt11 expression library was prepared. We screened the library with an absorbed anti-M. intracellulare serum and identified a recombinant phage which expressed a 190-kilodalton beta-galactosidase-M. intracellulare fusion protein. Lysates containing the 190-kilodalton fusion protein evoked strong humoral and cell-mediated responses. The immunoreactivity of the M. intracellulare recombinant protein suggests that antigens isolated from the expression library may be useful as skin test, serodiagnostic, or immunoprophylactic reagents for M. avium complex disease.
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PMID:Isolation and characterization of a recombinant lambda gt11 bacteriophage which expresses an immunoreactive Mycobacterium intracellulare protein in Escherichia coli. 246 Apr 5

The type D simian retroviruses cause immunosuppression in macaques and have been reported as a presumptive opportunistic infection in a patient with AIDS. Previous evidence based on viral interference has strongly suggested that the type D simian viruses share a common but unknown cell surface receptor with three type C viruses: feline endogenous virus (RD114), baboon endogenous virus, and avian reticuloendotheliosis virus. Furthermore, the receptor gene for these viruses has been mapped to human chromosome 19q13.1-13.2. We now report the isolation and characterization of a cell surface receptor for this group of retroviruses by using a human T-lymphocyte cDNA library in a retroviral vector. Swiss mouse fibroblasts (NIH 3T3), which are naturally resistant to RD114, were transduced with the retroviral library and then challenged with an RD114-pseudotyped virus containing a dominant selectable gene for puromycin resistance. Puromycin selection yielded 12 cellular clones that were highly susceptible to a beta-galactosidase-encoding lacZ(RD114) pseudotype virus. Using PCR primers specific for vector sequences, we amplified a common 2.9-kb product from 10 positive clones. Expression of the 2.9-kb cDNA in Chinese hamster ovary cells conferred susceptibility to RD114, baboon endogenous virus, and the type D simian retroviruses. The 2.9-kb cDNA predicted a protein of 541 amino acids that had 98% identity with the previously cloned human Na+-dependent neutral-amino-acid transporter Bo. Accordingly, expression of the RD114 receptor in NIH 3T3 cells resulted in enhanced cellular uptake of L-[3H]alanine and L-[3H]glutamine. RNA blot (Northern) analysis suggested that the RD114 receptor is widely expressed in human tissues and cell lines, including hematopoietic cells. The human Bo transporter gene has been previously mapped to 19q13.3, which is closely linked to the gene locus of the RD114 receptor.
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PMID:A sodium-dependent neutral-amino-acid transporter mediates infections of feline and baboon endogenous retroviruses and simian type D retroviruses. 1019 49