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Biomedical subjects

K Banerjee

Publications and source records attributed to K Banerjee.

At least 163 records · Page 9Linked to original sources
PubMed1988

The interaction of interferon-alpha and -gamma: regulation of (2-5)A synthetase activity.

The interaction of IFN-alpha and IFN-gamma on the induction of antiviral, growth inhibitory, and (2-5)A synthetase activities was investigated in T98G and A549 cells. Synergistic or inhibitory effects which were host-cell dependent were seen with both simultaneous and sequential IFN treatments. Interestingly, IFN-gamma 1 pretreatment affected the levels of IFN-alpha-induced (2-5)A synthetase activity differently in the two cell types. In T98G cells, sequential treatment resulted in an overall decrease in induction of enzyme activity that was not observed in A549 cells. Receptor binding assays and measurements of steady-state mRNA levels indicated that this effect of IFN-gamma pretreatment does not occur at the level of either receptor expression or induction of transcription of the low-molecular-weight form of (2-5)A synthetase.

2',5'-Oligoadenylate Synthetase↗
PubMed1988

Structure/function studies on recombinant human gamma interferon.

Structure/function relationships for human gamma interferon (IFN-gamma) were investigated using recombinant DNA-derived homologues produced in E. coli. The various biological effects examined were antiviral, growth inhibitory and 2-5A synthetase activities, as well as receptor binding characteristics. Specific structural changes led to IFN-gamma homologues with defined alterations in biological activities. Amino acid residue changes at the hydrophobic core of the molecule resulted in two homologues exhibiting loss of affinity for the IFN-gamma receptor and dramatically reduced biological activities. These diminished activities probably relate to the inability of the homologues to form appropriately folded structures. Residue changes at two sites associated with beta-turns on the surface of IFN-gamma likewise resulted in homologues with reduced biological activities. In these cases, the reduced biological activities were not associated with reduced receptor binding. Addition of cysteine-tyrosine-cysteine to the amino-terminus of IFN-gamma, known to perturb the protein conformation, slightly reduced the affinity of the so-derived homologue for the IFN-gamma receptor on T98G cells, and there was concommitant reduction in biological activities. Experiments with a monoclonal antibody that binds to the carboxy-terminus of IFN-gamma indicated that this region of the molecule may not influence antiviral or antiproliferative activities. Overall our data imply that several sites along the IFN-gamma polypeptide contribute to biological activity, and that receptor binding and effector sites are distinct.

2',5'-Oligoadenylate Synthetase↗