A state-of-the art protein analyses facility is maintained for NIAID scientists that includes mass spectrometers, protein sequencers, HPLCs, an amino acid analyzer and other ancillary equipment. About 300 samples were anlayzed by the facilities staff. In a collaborative study with the CDC, we showed that certain flavonoids, including chrysin, inhibit HIV-1 transcription in chronically infected cells by targeting an unidentified cellular factor. Several cellular proteins were isolated based on selective binding to chrysin; chemical and immunologic analyses identified them as the subunits of casein kinase II (CKII). A separate class of HIV-1 transcriptional inhibitors (benzothiophenes) which also act via an unknown mechanism also bound selectively to CKII. Chrysin and the benzothiophenes inhibited CKII enzymatic activity by competing with ATP, analogous to the classic CKII inhibitor DRB. Moreover, DRB inhibited HIV-1 expression in chronically infected cells. Thus, CKII may emerge as a novel cellular target for therapeutic intervention. Group B streptococci were recently reported to possess a cell-associated collagenase. In collaboration with the University of Alabama, we cloned and sequenced the gene for the enzyme (pepB). The deduced amino acid sequence showed 66.4% identity to the PepF oligopeptidase from Lactococcus lactis, a member of the M3 or thimet family of zinc metallopeptidases. The group B streptococcal enzyme also showed oligo peptidase activity and degraded a variety of small bioactive peptides, including bradykinin, neurotensin, and peptide fragments of substance P and adrenocorticotropin. Our data indicated that it was not a collagenase.
