scholarly journals Outer membrane phospholipase A in phospholipid bilayers: A model system for concerted computational and experimental investigations of amino acid side chain partitioning into lipid bilayers

2012 ◽  
Vol 1818 (2) ◽  
pp. 126-134 ◽  
Author(s):  
Patrick J. Fleming ◽  
J. Alfredo Freites ◽  
C. Preston Moon ◽  
Douglas J. Tobias ◽  
Karen G. Fleming
Keyword(s):  
Amino Acid ◽  
Outer Membrane ◽  
Lipid Bilayers ◽  
Model System ◽  
Phospholipid Bilayers ◽  
Phospholipase A ◽  
Side Chain ◽  
Experimental Investigations ◽  
Amino Acid Side Chain ◽  
Outer Membrane Phospholipase A

scholarly journals Talin activates integrins by altering the topology of the β transmembrane domain

2012 ◽  
Vol 197 (5) ◽  
pp. 605-611 ◽  
Author(s):  
Chungho Kim ◽  
Feng Ye ◽  
Xiaohui Hu ◽  
Mark H. Ginsberg
Keyword(s):  
Amino Acid ◽  
Ligand Binding ◽  
Outer Membrane ◽  
Transmembrane Domain ◽  
Side Chain ◽  
Amino Acid Side Chain ◽  
Integrin Activation ◽  
Integrin Αiibβ3 ◽  
Environmentally Sensitive ◽  
Extracellular Side

Talin binding to integrin β tails increases ligand binding affinity (activation). Changes in β transmembrane domain (TMD) topology that disrupt α–β TMD interactions are proposed to mediate integrin activation. In this paper, we used membrane-embedded integrin β3 TMDs bearing environmentally sensitive fluorophores at inner or outer membrane water interfaces to monitor talin-induced β3 TMD motion in model membranes. Talin binding to the β3 cytoplasmic domain increased amino acid side chain embedding at the inner and outer borders of the β3 TMD, indicating altered topology of the β3 TMD. Talin’s capacity to effect this change depended on its ability to bind to both the integrin β tail and the membrane. Introduction of a flexible hinge at the midpoint of the β3 TMD decoupled the talin-induced change in intracellular TMD topology from the extracellular side and blocked talin-induced activation of integrin αIIbβ3. Thus, we show that talin binding to the integrin β TMD alters the topology of the TMD, resulting in integrin activation.

Outer Membrane Phospholipase A Is Dimeric in Phospholipid Bilayers:  A Cross-Linking and Fluorescence Resonance Energy Transfer Study†

Biochemistry ◽  
1999 ◽  
Vol 38 (22) ◽  
pp. 7398-7405 ◽  
Author(s):  
Iban Ubarretxena-Belandia ◽  
Leo Hozeman ◽  
Els van der Brink-van der Laan ◽  
Eward H. M. Pap ◽  
Maarten R. Egmond ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Outer Membrane ◽  
Fluorescence Resonance Energy Transfer ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Phospholipid Bilayers ◽  
Phospholipase A ◽  
Cross Linking ◽  
Outer Membrane Phospholipase A ◽  
Transfer Study

Amino acid side-chain populations in aqueous and saline solution: Bis-penicillamine enkephalin

Biopolymers ◽  
1992 ◽  
Vol 32 (12) ◽  
pp. 1623-1629 ◽  
Author(s):  
Paul E. Smith ◽  
B. Montgomery Pettitt
Keyword(s):  
Amino Acid ◽  
Saline Solution ◽  
Side Chain ◽  
Amino Acid Side Chain

Effect of charged amino acid side chain length on lateral cross-strand interactions between carboxylate- and guanidinium-containing residues in a β-hairpin

Amino Acids ◽  
2015 ◽  
Vol 47 (5) ◽  
pp. 885-898 ◽  
Author(s):  
Hsiou-Ting Kuo ◽  
Shing-Lung Liu ◽  
Wen-Chieh Chiu ◽  
Chun-Jen Fang ◽  
Hsien-Chen Chang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Chain Length ◽  
Side Chain ◽  
Amino Acid Side Chain ◽  
Side Chain Length

scholarly journals Absence of the Outer Membrane Phospholipase A Suppresses the Temperature-Sensitive Phenotype of Escherichia coli degPMutants and Induces the Cpx and ςE Extracytoplasmic Stress Responses

2001 ◽  
Vol 183 (18) ◽  
pp. 5230-5238 ◽  
Author(s):  
Geoffrey R. Langen ◽  
Jill R. Harper ◽  
Thomas J. Silhavy ◽  
S. Peter Howard
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
Stress Responses ◽  
Elevated Temperatures ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Phospholipase A ◽  
Temperature Sensitive ◽  
Outer Membrane Phospholipase A ◽  
Temperature Sensitive Phenotype

ABSTRACT DegP is a periplasmic protease that is a member of both the ςE and Cpx extracytoplasmic stress regulons ofEscherichia coli and is essential for viability at temperatures above 42°C. [U-14C]acetate labeling experiments demonstrated that phospholipids were degraded indegP mutants at elevated temperatures. In addition, chloramphenicol acetyltransferase, β-lactamase, and β-galactosidase assays as well as sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis indicated that large amounts of cellular proteins are released from degP cells at the nonpermissive temperature. A mutation in pldA, which encodes outer membrane phospholipase A (OMPLA), was found to rescue degPcells from the temperature-sensitive phenotype. pldA degP mutants had a normal plating efficiency at 42°C, displayed increased viability at 44°C, showed no degradation of phospholipids, and released far lower amounts of cellular protein to culture supernatants. degP and pldA degP mutants containing chromosomal lacZ fusions to Cpx and ςE regulon promoters indicated that both regulons were activated in the pldA mutants. The overexpression of the envelope lipoprotein, NlpE, which induces the Cpx regulon, was also found to suppress the temperature-sensitive phenotype ofdegP mutants but did not prevent the degradation of phospholipids. These results suggest that the absence of OMPLA corrects the degP temperature-sensitive phenotype by inducing the Cpx and ςE regulons rather than by inactivating the phospholipase per se.

scholarly journals Topology of the outer membrane phospholipase A of Salmonella typhimurium.

1997 ◽  
Vol 179 (11) ◽  
pp. 3443-3450 ◽  
Author(s):  
K B Merck ◽  
H de Cock ◽  
H M Verheij ◽  
J Tommassen
Keyword(s):  
Salmonella Typhimurium ◽  
Outer Membrane ◽  
Phospholipase A ◽  
Outer Membrane Phospholipase A
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