scholarly journals Nucleotides bind to the C-terminus of ClC-5

2006 ◽  
Vol 398 (2) ◽  
pp. 289-294 ◽  
Author(s):  
Leigh Wellhauser ◽  
Hsin-Hen Kuo ◽  
Fiona L. L. Stratford ◽  
Mohabir Ramjeesingh ◽  
Ling-Jun Huan ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Secondary Structure ◽  
Chloride Ion ◽  
Helical Structure ◽  
Biophysical Properties ◽  
C Terminus ◽  
Cd Studies ◽  
Cbs Domains ◽  
Chloride Ion Channels ◽  
Thermal Stability Of

Mutations in ClC-5 (chloride channel 5), a member of the ClC family of chloride ion channels and antiporters, have been linked to Dent's disease, a renal disease associated with proteinuria. Several of the disease-causing mutations are premature stop mutations which lead to truncation of the C-terminus, pointing to the functional significance of this region. The C-terminus of ClC-5, like that of other eukaryotic ClC proteins, is cytoplasmic and contains a pair of CBS (cystathionine β-synthase) domains connected by an intervening sequence. The presence of CBS domains implies a regulatory role for nucleotide interaction based on studies of other unrelated proteins bearing these domains [Ignoul and Eggermont (2005) Am. J. Physiol. Cell Physiol. 289, C1369–C1378; Scott, Hawley, Green, Anis, Stewart, Scullion, Norman and Hardie (2004) J. Clin. Invest. 113, 274–284]. However, to date, there has been no direct biochemical or biophysical evidence to support nucleotide interaction with ClC-5. In the present study, we have expressed and purified milligram quantities of the isolated C-terminus of ClC-5 (CIC-5 Ct). CD studies show that the protein is compact, with predominantly α-helical structure. We determined, using radiolabelled ATP, that this nucleotide binds the folded protein with low affinity, in the millimolar range, and that this interaction can be competed with 1 μM AMP. CD studies show that binding of these nucleotides causes no significant change in secondary structure, consistent with a model wherein these nucleotides bind to a preformed site. However, both nucleotides induce an increase in thermal stability of ClC-5 Ct, supporting the suggestion that both nucleotides interact with and modify the biophysical properties of this protein.

Effect of ketoprofen-based ionic liquids on secondary structure and thermal stability of human serum albumin

2020 ◽  
Vol 142 (5) ◽  
pp. 1911-1917
Author(s):  
Proletina Kardaleva ◽  
Maya Guncheva ◽  
Svetla Todinova ◽  
Ivan Angelov ◽  
Paula Ossowicz ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ionic Liquids ◽  
Secondary Structure ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Thermal Stability Of

scholarly journals Thermal stability of the helical structure of type IV collagen within basement membranes in situ: determination with a conformation-dependent monoclonal antibody.

1984 ◽  
Vol 99 (4) ◽  
pp. 1405-1409 ◽  
Author(s):  
T F Linsenmayer ◽  
E Gibney ◽  
J M Fitch ◽  
J Gross ◽  
R Mayne
Keyword(s):  
Thermal Stability ◽  
Type Iv Collagen ◽  
Helical Structure ◽  
Basement Membranes ◽  
Enzyme Linked Immunosorbent Assay ◽  
Tissue Sections ◽  
Type Iv ◽  
The Stability ◽  
Thermal Stability Of

To examine the thermal stability of the helical structure of type IV collagen within basement membranes in situ, we have employed indirect immunofluorescence histochemistry performed at progressively higher temperatures using a conformation-dependent antibody, IV-IA8. We previously observed by competition enzyme-linked immunosorbent assay that, in neutral solution, the helical epitope to which this antibody binds undergoes thermal denaturation over the range of 37-40 degrees C. In the present study, we have reacted unfixed cryostat tissue sections with this antibody at successively higher temperatures. We have operationally defined denaturation as the point at which type IV-specific fluorescence is no longer detectable. Under these conditions, the in situ denaturation temperature of this epitope in most basement membranes is 50-55 degrees C. In capillaries and some other small blood vessels the fluorescent signal is still clearly detectable at 60 degrees C, the highest temperature at which we can confidently use this technique. We conclude that the stability of the helical structure of type IV collagen within a basement membrane is considerably greater than it is in solution, and that conformation-dependent monoclonal antibodies can be useful probes for investigations of molecular structure in situ.

N-glycosylation analysis of the human Tweety family of putative chloride ion channels supports a penta-spanning membrane arrangement: impact of N-glycosylation on cellular processing of Tweety homologue 2 (TTYH2)

2008 ◽  
Vol 412 (1) ◽  
pp. 45-55 ◽  
Author(s):  
Yaowu He ◽  
Andrew J. Ramsay ◽  
Melanie L. Hunt ◽  
Astrid K. Whitbread ◽  
Stephen A. Myers ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Chloride Ion ◽  
Glycosylation Site ◽  
C Terminus ◽  
Cl Channels ◽  
Cellular Processing ◽  
Site Mutagenesis ◽  
Membrane Spanning ◽  
Chloride Ion Channels ◽  
Membrane Spanning Domains

The Tweety proteins are a family of recently identified putative Cl− channels predicted to be modified by N-glycosylation and, controversially, to contain five or six membrane-spanning domains, leading to the contentious proposal that members of this family do not share the same topology at the plasma membrane. In humans, three family members have been identified, designated TTYH1 (Tweety homologue 1), TTYH2 and TTYH3. To gain greater insight into the arrangement of membrane-spanning domains and cellular processing of Tweety proteins, in the present study we have examined the sequence homology, hydrophobicity and N-glycan content of members of this family and performed N-glycosylation site-mutagenesis studies on TTYH2 and TTYH3. Based on these observations we propose a structure for Tweety family proteins which incorporates five membrane-spanning domains with a topology at the cell surface in which the N-terminus is located extracellularly and the C-terminus cytoplasmically. Our results also suggest that N-glycosylation is important, but not essential, in the processing of members of the Tweety family with results indicating that, although incomplete N-glycosylation mediates reduced expression and increased ubiquitination of TTYH2, N-glycosylation is not the determining factor for TTYH2 trafficking to the plasma membrane. This information will be important for the characterization of Tweety family proteins in normal physiology and disease.

The Physical Properties of Tripeptide Stereocomplex Nano-Formations

2020 ◽  
Vol 16 (10) ◽  
pp. 1495-1503
Author(s):  
Alaa F. Nahhas ◽  
Alrayan F. Nahhas ◽  
Thomas J. Webster
Keyword(s):  
Thermal Stability ◽  
Aqueous Solution ◽  
Wound Healing ◽  
Physical Properties ◽  
Medical Applications ◽  
Physiological Conditions ◽  
New Class ◽  
Left Handed ◽  
C Terminus ◽  
Thermal Stability Of

The fast-growing use of supramolecular hydrogelators as biomaterials for a variety of applications, ranging from wound healing to drug delivery to tissue engineering, has highlighted the importance of synthetic design over recent years. Here, we report a new class of nanosheet stereocomplexes in aqueous solution and at physiological conditions (i. e., pH7.4), which are formed by physically mixing right- and left-handed tripeptide supramolecular hydrogelators without any external stimulus. Such tripeptides were obtained by incorporating either α-aminoisobutyric acid (Aib, U) or alanine (Ala, A) at the C-terminus or middle position of known peptide hydrogelators containing naphthalene and two phenylalanine residues. For hydrogels of these peptides, our results show that their morphologies and physical properties changed upon mixing with the L- and D-forms of the peptides forming suspension stereocomplexes. These interactions reduced molecular mobility by forming new structures with new properties and, therefore, increased the thermal stability of the compound promising for numerous medical applications.

scholarly journals Biophysical properties and thermal stability of oligonucleotides of RNA containing 7,8‐dihydro‐8‐hydroxyadenosine

Biopolymers ◽  
2014 ◽  
Vol 103 (3) ◽  
pp. 167-174 ◽  
Author(s):  
Ana M. Chauca‐Diaz ◽  
Yu Jung Choi ◽  
Marino J. E. Resendiz
Keyword(s):  
Thermal Stability ◽  
Biophysical Properties ◽  
Thermal Stability Of
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