ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthetic peptides as models for ion channel proteinsKarin S. Akerfeldt, Jim D. Lear, Zelda R. Wasserman, Laura A. Chung, and William F. DeGradoCite this: Acc. Chem. Res. 1993, 26, 4, 191–197Publication Date (Print):April 1, 1993Publication History Published online1 May 2002Published inissue 1 April 1993https://pubs.acs.org/doi/10.1021/ar00028a009https://doi.org/10.1021/ar00028a009research-articleACS PublicationsRequest reuse permissionsArticle...

Nanofibrillar forms of proteins were initially recognized in the context pathology, but more recently have been discovered a range functional roles nature, including as active catalytic scaffolds and bacterial coatings. Here we show that protein nanofibrils can be used to form basis monodisperse microgels gel shells composed naturally occurring proteins. We explore potential these act drug carrier agents, demonstrate controlled release four different encapsulated drug-like small molecules,...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTetraphilin: a four-helix proton channel built on tetraphenylporphyrin frameworkKarin S. Akerfeldt, Ronald M. Kim, Daniel Camac, John T. Groves, Jim D. Lear, and William F. DeGradoCite this: J. Am. Chem. Soc. 1992, 114, 24, 9656–9657Publication Date (Print):November 1, 1992Publication History Published online1 May 2002Published inissue 1 November 1992https://pubs.acs.org/doi/10.1021/ja00050a054https://doi.org/10.1021/ja00050a054research-articleACS...

Calbindin D_28k is a member of the calmodulin superfamily Ca²⁺-binding proteins and contains six EF-hands. The protein generally believed to function as Ca²⁺ buffer, but studies presented in this work indicate that it may also act sensor. results show Mg²⁺ binds same sites Ca²⁺with an association constant ∼1.4·10³m⁻¹ 0.15 m KCl. four high affinity calbindin bind non-sequential, parallel manner. In presence...

The 11-residue peptide GSFSIQYTYHV from human semenogelin I forms a hydrogel with optimal stability at pH 7–9.

Determining the pKa of key functional groups is critical to understanding pH-dependent behavior biological proteins and peptide-based biomaterials. Traditionally, ¹H NMR spectroscopy has been used determine amino acids; however, for larger molecules aggregating systems, this method can be practically impossible. Previous studies concluded that C-D stretches in Raman are a useful alternative determining histidine residues. In study, we report on application C2-D probe histidine's imidazole...

Self-assembling peptide-based hydrogels are a class of tunable soft materials that have been shown to be highly useful for number biomedical applications. The dynamic formation the supramolecular fibrils compose these has heretofore remained poorly characterized. A better understanding this process would provide important insights into behavior systems and could aid in rational design new peptide hydrogels. Here, we report determination microscopic steps underpin self-assembly...

Calmodulin is an essential regulator of intracellular processes in response to extracellular stimuli mediated by a rise Ca(2+) ion concentration. To profile protein-protein interactions calmodulin human brain, we probed high content protein array with fluorophore-labeled the presence Ca(2+). This contains 37,200 redundant proteins, incorporating over 10,000 unique neural proteins from brain cDNA library. We designed screen find affinity (K(D) < or = 1 microm) binding partners and identified...

Abstract Peptides and proteins have evolved to self‐assemble into supramolecular entities through a set of non‐covalent interactions. Such structures materials provide the functional basis life. Crucially, biomolecular assembly processes can be highly sensitive modulated by environmental conditions, including temperature, light, ionic strength pH, providing inspiration for development new classes responsive based on peptide building blocks. Here, it is shown that stimuli‐responsive...

We report the synthesis and characterization of a novel supramolecular assembly that features long-range electronic coupling between porphyrins covalently attached to designed peptide scaffold. The resulting construct self-assembles form extended organized aggregates in which engage exciton coupling.

Abstract Calbindin D 28k is an intracellular Ca 2+ ‐binding protein containing six subdomains of EF‐hand type. The number and identity the globular domains within this have been elucidated using synthetic peptide fragments, each corresponding to one subdomain. All peptides were mixed in equimolar amounts presence 10 mM allow for reconstitution domains. mixture was compared native calbindin sum properties individual circular dichroism (CD), fluorescence, 1 H NMR spectroscopy, as well gel...

Calbindin D28k is an intracellular Ca2+-binding protein noted for its abundance and specific distribution in mammalian brain sensory neurons. This contains six putative sites, referred to as EF-hands. Due the presence of large number previous studies have been unsuccessful definitively establishing stoichiometry Ca2+ binding. We describe a synthetic approach identify sites which 6 33-residue peptides, designated EF1−EF6, corresponding EF-hand sequences calbindin D28k, were made. The response...

P450 monooxygenase enzyme ComJ catalyzed biaryl ether bond formation with high efficiency and low stereoselectivity on selected complestatin-like peptide substrates.

Calbindin D(28k) (calbindin) is a cytoplasmic protein expressed in the central nervous system, which implied Ca(2+) homeostasis and enzyme regulation. A combination of biochemical methods mass spectrometry has been used to identify post-translational modifications human calbindin. The was studied at 37 degrees C or 50 presence absence Ca(2+). One deamidation site identified position 203 (Asn) under all conditions. Kinetic experiments show that Asn occurs rate 0.023 h(-1) for Ca(2+)-free...

The use of manufactured nanomaterials is rapidly increasing, while our understanding the consequences releasing these materials into environment still limited and many questions remain, for example, how do nanoparticles affect living organisms in wild? How adapt protect themselves from exposure to foreign materials? does performance nanoparticles, including their surface properties? In an effort address crucial questions, main aim has been probe effects aquatic on nanoparticle aggregation....

An N-terminal cysteine is used to displace bromide from a bromoacetylated porphyrin yield thioether linkage between the peptide and template. Unlike amide coupling reactions, this approach should be compatible with any sequence provided there only single cysteine.

This study explores the influence of long‐range intra‐protein electrostatic interactions on conformation calmodulin in solution. Ensemble F örster resonance energy transfer ( FRET ) is measured for with a fluorophore pair incorporated specifically donor at residue 17 and an acceptor position 117. construct was generated by combination solid phase peptide synthesis, cloning, expression native chemical ligation. labelling method has not previously been used represents convenient ensuring...

Human calbindin D28k is a Ca2+ binding protein that has been implicated in the protection of cells against apoptosis. In this study, structural and functional significance five cysteine residues present have investigated through series cysteine-to-serine mutations. The mutants were studied under relevant physiological redox potentials which conformational changes monitored using ANS binding. Urea-induced denaturations, as by intrinsic tryptophan fluorescence, also carried out to compare...

Ribosomes are the protein factories of every living cell. The process translation is highly complex and tightly regulated by a large number diverse RNAs proteins. Earlier studies indicate that Ca(2+) plays role in translation. Calmodulin (CaM), ubiquitous Ca(2+)-binding protein, regulates proteins participating many signaling pathways. Several 40S 60S ribosomal have been identified to interact with CaM, here, we report CaM binds high affinity 80S ribosomes polyribosomes Ca(2+)-dependent...

Calbindin D28k, a highly conserved protein with Ca2+-sensing and Ca2+-buffering capabilities, is abundant in brain sensory neurons. This contains six EF-hand subdomains, four of which bind Ca2+ high affinity. D28k can be reconstituted from synthetic peptides corresponding to the EF-hands, indicating single-domain structure multiple interactions between subdomains. In this study, we have undertaken detailed characterization Ca2+-binding oligomerization properties each individual peptide using...

A porphyrin-tethered construct, containing four full-length alamethicin monomers, has been synthesized and characterized. The ion conductance data of the assembly in 1 M HCl display long-lived, albeit noisy, channels that appear to be voltage-independent multiples only one state. noise is consistent with molecular modeling studies, which indicate side chain glutamine 7 does not fit well into narrow pore a parallel four-helix bundle.