Judy Luke
Author's posts
Apr 08 2005
Intramolecular cooperativity in a protein binding site assessed by combinatorial shotgun scanning mutagenesis
Pál G, Ultsch MH, Clark KP, Currell B, Kossiakoff AA, Sidhu SS
J. Mol. Biol. 2005 Apr;347(3):489-94
PMID: 15755445
Abstract
Combinatorial shotgun alanine-scanning was used to assess intramolecular cooperativity in the high affinity site (site 1) of human growth hormone (hGH) for binding to its receptor. A total of 19 side-chains were analyzed and statistically …
Jan 08 2005
The crystal structure of a quercetin 2,3-dioxygenase from Bacillus subtilis suggests modulation of enzyme activity by a change in the metal ion at the active site(s)
Gopal B, Madan LL, Betz SF, Kossiakoff AA
Biochemistry 2005 Jan;44(1):193-201
PMID: 15628860
Abstract
Common structural motifs, such as the cupin domains, are found in enzymes performing different biochemical functions while retaining a similar active site configuration and structural scaffold. The soil bacterium Bacillus subtilis has 20 cupin genes (0.5% of the total genome) with …
Dec 08 2004
The high- and low-affinity receptor binding sites of growth hormone are allosterically coupled
Walsh ST, Sylvester JE, Kossiakoff AA
Proc. Natl. Acad. Sci. U.S.A. 2004 Dec;101(49):17078-83
PMID: 15563602
Abstract
Growth hormone regulates its biological properties via a sequential hormone-induced receptor homodimerization mechanism. Using a mutagenesis-scanning analysis of 81 single and 32 pairwise double mutations, we show that the hormone’s two spatially distal receptor binding sites (Site1 and Site2) …
Jun 08 2004
The structural basis for biological signaling, regulation, and specificity in the growth hormone-prolactin system of hormones and receptors
Kossiakoff AA
Adv. Protein Chem. 2004;68:147-69
PMID: 15500861
Abstract
The pituitary hormones growth hormone (GH), prolactin (PRL) and placental lactogen (PL), are members of an extensive cytokine superfamily of hormones and receptors that share many of the same general structure-function relationships in expressing their biological activities. The biology of the pituitary hormones involves a very …
May 08 2004
Dissecting the binding energy epitope of a high-affinity variant of human growth hormone: cooperative and additive effects from combining mutations from independently selected phage display mutagenesis libraries
Bernat B, Sun M, Dwyer M, Feldkamp M, Kossiakoff AA
Biochemistry 2004 May;43(20):6076-84
PMID: 15147191
Abstract
Phage display mutagenesis is a widely used approach to engineering novel protein properties and is especially powerful in probing structure-function relationships in molecular recognition processes. The relative contributions of additive and cooperative binding forces and the influence of conformational …
Sep 08 2003
Site2 binding energetics of the regulatory step of growth hormone-induced receptor homodimerization
Walsh ST, Jevitts LM, Sylvester JE, Kossiakoff AA
Protein Sci. 2003 Sep;12(9):1960-70
PMID: 12930995
Abstract
Receptor signaling in the growth hormone (GH)-growth hormone receptor (GHR) system is controlled through a sequential two-step hormone-induced dimerization of two copies of the extracellular domain (ECD) of the receptor. The regulatory step of this process is the binding of …
Sep 08 2003
The functional binding epitope of a high affinity variant of human growth hormone mapped by shotgun alanine-scanning mutagenesis: insights into the mechanisms responsible for improved affinity
Pal G, Kossiakoff AA, Sidhu SS
J. Mol. Biol. 2003 Sep;332(1):195-204
PMID: 12946357
Abstract
A high-affinity variant of human growth hormone (hGH(v)) contains 15 mutations within site 1 and binds to the hGH receptor (hGHR) approximately 400-fold tighter than does wild-type (wt) hGH (hGH(wt)). We used shotgun scanning combinatorial mutagenesis to dissect the energetic contributions …
Jun 08 2003
The first semi-synthetic serine protease made by native chemical ligation
Pál G, Santamaria F, Kossiakoff AA, Lu W
Protein Expr. Purif. 2003 Jun;29(2):185-92
PMID: 12767808
Abstract
Selective incorporation of non-natural amino acid residues into proteins is a powerful approach to delineate structure-function relationships. Although many methodologies are available for chemistry-based protein engineering, more facile methods are needed to make this approach suitable for routine laboratory …
Feb 08 2003
Determination of the energetics governing the regulatory step in growth hormone-induced receptor homodimerization
Bernat B, Pal G, Sun M, Kossiakoff AA
Proc. Natl. Acad. Sci. U.S.A. 2003 Feb;100(3):952-7
PMID: 12552121
Abstract
Signaling in the human growth hormone (hGH)-human GH receptor system is initiated by a controlled sequential two-step hormone-induced dimerization of two hGH receptors via their extracellular domains (ECDs). Little is currently known about the energetics governing the …
Feb 08 2002
Structure of a phage display-derived variant of human growth hormone complexed to two copies of the extracellular domain of its receptor: evidence for strong structural coupling between receptor binding sites
Schiffer C, Ultsch M, Walsh S, Somers W, de Vos AM, Kossiakoff A
J. Mol. Biol. 2002 Feb;316(2):277-89
PMID: 11851338
Abstract
The structure of the ternary complex between the phage display- optimized, high-affinity Site 1 variant of human growth hormone (hGH) and two copies of the extracellular domain (ECD) of the hGH receptor (hGHR) has …