Steven C Koerber

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We have characterized a phosphoserine binding domain in the coactivator CREB-binding protein (CBP) which interacts with the protein kinase A-phosphorylated, and hence activated, form of the cyclic AMP-responsive factor CREB. The CREB binding domain, referred to as KIX, is alpha helical and binds to an unstructured kinase-inducible domain in CREB following(More)
We present evidence that members of the corticotropin releasing factor (CRF) family assume distinct structures when interacting with the CRF(1) and CRF(2) receptors. Predictive methods, physicochemical measurements, and structure-activity relationship studies have suggested that CRF, its family members, and competitive antagonists such as astressin(More)
Predictive methods, physicochemical measurements, and structure activity relationship studies suggest that corticotropin-releasing factor (CRF; corticoliberin), its family members, and competitive antagonists (resulting from N-terminal deletions) usually assume an alpha-helical conformation when interacting with the CRF receptor(s). To test this hypothesis(More)
The heptahelical receptors for corticotropin-releasing factor (CRF), CRFR1 and CRFR2, display different specificities for CRF family ligands: CRF and urocortin I bind to CRFR1 with high affinity, whereas urocortin II and III bind to this receptor with very low affinities. In contrast, all the urocortins bind with high affinities, and CRF binds with lower(More)
The kinetic mechanism of monoamine oxidase B involves either a binary or a ternary complex, depending on the substrate. In this study, stopped-flow kinetic data provide direct evidence for ternary complexes not only of reduced enzyme, oxygen, and product but also of reduced enzyme, oxygen, and substrate, both for benzylamine and for the tertiary amine(More)
To further elucidate the minimum bioactive conformation of neuropeptide Y (NPY), a series of truncated and conformationally constrained analogues has been prepared. The synthesis and purification of these peptides was achieved using routine laboratory strategies and techniques. Parent molecules consisted of the native NPY N-terminal 1-4 and C-terminal 25-36(More)
While the clinical significance of gonadotrophin-releasing hormone (GnRH) agonists is well recognized, the potential use of GnRH antagonists in humans awaits the availability of potent analogues with no untoward side-effects. We have designed, synthesized and tested several hundred linear and cyclic analogues (agonists and antagonists) of GnRH in different(More)
Neuropeptide Y (NPY), a 36-residue polypeptide produced abundantly in both nervous and peripheral tissues, appears to play a significant role in the regulation of diverse biological processes, including feeding behavior and cardiovascular and psychotropic functions. The actions of NPY are mediated through effective binding to specific receptors of which(More)
The 3D NMR structures of six octapeptide agonist analogues of somatostatin (SRIF) in the free form are described. These analogues, with the basic sequence H-DPhe/Phe2-c[Cys3-Xxx7-DTrp8-Lys9-Thr10-Cys14]-Thr-NH2 (the numbering refers to the position in native SRIF), with Xxx7 being Ala/Aph, exhibit potent and highly selective binding to human SRIF type 2(More)