Synthesis and Conformational Transition of Surface-Tethered Polypeptide:  Poly(l-glutamic acid)

2003 ◽  
Vol 36 (17) ◽  
pp. 6503-6510 ◽  
Author(s):  
Yuli Wang ◽  
Ying Chih Chang
Keyword(s):  
Glutamic Acid ◽  
Conformational Transition

Photoinduced conformational transition of polypeptide membrane composed of poly(L-glutamic acid) containing pararosaniline groups in the side chains

1988 ◽  
Vol 21 (12) ◽  
pp. 3419-3424 ◽  
Author(s):  
Morimasa Sato ◽  
Takatoshi Kinoshita ◽  
Akira Takizawa ◽  
Yoshiharu Tsujita
Keyword(s):  
Glutamic Acid ◽  
Conformational Transition ◽  
Side Chains

scholarly journals Glutamic acid 327 in the sheep α 1 isoform of Na+,K+-ATPase is a pivotal residue for cation-induced conformational changes

1995 ◽  
Vol 309 (1) ◽  
pp. 187-194 ◽  
Author(s):  
C L Johnson ◽  
T A Kuntzweiler ◽  
J B Lingrel ◽  
C G Johnson ◽  
E T Wallick
Keyword(s):  
Glutamic Acid ◽  
Conformational Changes ◽  
Conformational Transition ◽  
Cation Binding ◽  
Monovalent Cations ◽  
Wild Type ◽  
Binding Studies ◽  
Ouabain Binding ◽  
Na Ions ◽  
Inhibition Curve

The cation binding characteristics of the mutant E327A formed in the sheep alpha 1 isoform of the Na+,K(+)-ATPase were examined using [3H]ouabain binding as a function of monovalent cation concentrations. Equilibrium competition binding assays in the presence of Mg2+, inorganic phosphate and various amounts of unlabelled ouabain indicated that both wild-type sheep alpha 1 protein and the E327A mutant expressed in 3T3 cells had similar affinities for ouabain (KD = 1.53 and 1.31 nM respectively). Sodium inhibition of ouabain binding appeared competitive in both enzymes. However, binding of three Na+ ions was required to explain the steep character of the Na+ inhibition curve for the wild-type Na+,K(+)-ATPase (Ki = 12.8 +/- 1.6 mM), whereas the binding of two Na+ ions was detected for the mutant E327A (Ki = 19.2 +/- 2.5 mM). Potassium binding of [3H]ouabain binding displayed a partially competitive nature with Hill coefficients of 2 for both wild-type sheep alpha 1 (Ki = 0.743 +/- 0.044 mM) and E327A (Ki = 0.875 +/- 0.067 mM). At concentrations of K+ above 10 mM, the sheep alpha 1 competition curve levelled off whereas the inhibition curve for E327A displayed a stimulation in ouabain binding. This stimulation in [3H]ouabain binding also occurred with Rb+, Cs+ and Li+, but was never observed with choline or Na+, suggesting that this effect was not due to ionic strength. From these [3H]ouabain-binding studies, it is obvious that the mutant enzyme E327A in the presence of Mg2+, Pi and ouabain, interacts with monovalent cations in a unique fashion. One interpretation of these data is that the glutamic acid residue at position 327 is involved in a conformational transition induced by the binding of monovalent cations to the Na+,K+-ATPase and that this transition is inhibited by the mutation of E327A.

Conformational transition of poly(α-l-glutamic acid)

1989 ◽  
Vol 34 (3) ◽  
pp. 301-309 ◽  
Author(s):  
S. Paoletti ◽  
A. Cesàro ◽  
C.Arce Amper ◽  
J.C. Benegas
Keyword(s):  
Glutamic Acid ◽  
Conformational Transition

Conformational transition of poly(L-glutamic acid) in aqueous solution

Biopolymers ◽  
1966 ◽  
Vol 4 (5) ◽  
pp. 529-538 ◽  
Author(s):  
G. Barone ◽  
V. Crescenzi ◽  
F. Quadrifoglio
Keyword(s):  
Aqueous Solution ◽  
Glutamic Acid ◽  
Conformational Transition

scholarly journals Toggle switch residues control allosteric transitions in bacterial adhesins by participating in a concerted repacking of the protein core

2021 ◽  
Vol 17 (4) ◽  
pp. e1009440
Author(s):  
Dagmara I. Kisiela ◽  
Pearl Magala ◽  
Gianluca Interlandi ◽  
Laura A. Carlucci ◽  
Angelo Ramos ◽  
...  
Keyword(s):  
Glutamic Acid ◽  
Protein Function ◽  
Conformational Transition ◽  
Binding Pocket ◽  
Toggle Switch ◽  
Molecular Events ◽  
Bacterial Adhesins ◽  
Mannose Binding ◽  
Allosteric Transitions ◽  
Fimbrial Adhesins

Critical molecular events that control conformational transitions in most allosteric proteins are ill-defined. The mannose-specific FimH protein of Escherichia coli is a prototypic bacterial adhesin that switches from an ‘inactive’ low-affinity state (LAS) to an ‘active’ high-affinity state (HAS) conformation allosterically upon mannose binding and mediates shear-dependent catch bond adhesion. Here we identify a novel type of antibody that acts as a kinetic trap and prevents the transition between conformations in both directions. Disruption of the allosteric transitions significantly slows FimH’s ability to associate with mannose and blocks bacterial adhesion under dynamic conditions. FimH residues critical for antibody binding form a compact epitope that is located away from the mannose-binding pocket and is structurally conserved in both states. A larger antibody-FimH contact area is identified by NMR and contains residues Leu-34 and Val-35 that move between core-buried and surface-exposed orientations in opposing directions during the transition. Replacement of Leu-34 with a charged glutamic acid stabilizes FimH in the LAS conformation and replacement of Val-35 with glutamic acid traps FimH in the HAS conformation. The antibody is unable to trap the conformations if Leu-34 and Val-35 are replaced with a less bulky alanine. We propose that these residues act as molecular toggle switches and that the bound antibody imposes a steric block to their reorientation in either direction, thereby restricting concerted repacking of side chains that must occur to enable the conformational transition. Residues homologous to the FimH toggle switches are highly conserved across a diverse family of fimbrial adhesins. Replacement of predicted switch residues reveals that another E. coli adhesin, galactose-specific FmlH, is allosteric and can shift from an inactive to an active state. Our study shows that allosteric transitions in bacterial adhesins depend on toggle switch residues and that an antibody that blocks the switch effectively disables adhesive protein function.

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