ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTComparison of the transient folding intermediates in lysozyme and .alpha.-lactalbuminKunihiro Kuwajima, Yoshiki Hiraoka, Masamichi Ikeguchi, Shintaro SugaiCite this: Biochemistry 1985, 24, 4, 874–881Publication Date (Print):February 1, 1985Publication History Published online1 May 2002Published inissue 1 February 1985https://pubs.acs.org/doi/10.1021/bi00325a010https://doi.org/10.1021/bi00325a010research-articleACS PublicationsRequest reuse...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEvidence for identity between the equilibrium unfolding intermediate and a transient folding intermediate: comparative study of reactions .alpha.-lactalbumin lysozymeMasamichi Ikeguchi, Kunihiro Kuwajima, Masahiro Mitani, Shintaro SugaiCite this: Biochemistry 1986, 25, 22, 6965–6972Publication Date (Print):November 4, 1986Publication History Published online1 May 2002Published inissue 4 November...

A large number of studies have been carried out to obtain amino acid propensities for α-helices and β-sheets. The obtained are consistent with each other, the pair-wise correlation coefficient is frequently high. On other hand, β-sheet by several differed significantly, indicating that context significantly affects propensity.We calculated β-sheets 39 24 protein folds, respectively, addressed whether they correlate fold. were also exposed buried sites, respectively. Results showed α-helix do...

Journal Article Ca2+ Alteration in the Unfolding Behavior of α-Lactalbumin Get access Masamichi IKEGUCHI, IKEGUCHI Department Polymer Science, Faculty Hokkaido UniversityKita-ku, Sapporo, 060 Search for other works by this author on: Oxford Academic PubMed Google Scholar Kunihiro KUWAJIMA, KUWAJIMA Shintaro SUGAI The Biochemistry, Volume 99, Issue 4, April 1986, Pages 1191–1201, https://doi.org/10.1093/oxfordjournals.jbchem.a135582 Published: 01 1986 history Received: 06 December 1985

Kinetics of disulfide reduction in alpha-lactalbumin by dithiothreitol are investigated measuring time-dependent changes absorption at 310 nm and CD ellipticity 270 (pH 8.5 or 7.0, 25 degrees C). When the disulfide-intact protein is folded, kinetics biphasic. The bond between half-cystines-6 -120 reduced fast phase, other three bonds slow phase. apparent rate constants two phases both proportional to concentration dithiothreitol, indicating that expressed bimolecular reactions. However,...

The assembly reaction of Escherichia coli ferritin A (EcFtnA) was studied using time-resolved small-angle X-ray scattering (TR-SAXS). EcFtnA forms a cagelike structure that consists 24 identical subunits and dissociates into dimers at acidic pH. dimer maintains nativelike secondary tertiary structures is able to reassemble 24-mer when the pH increased. reassembly induced by jump, followed TR-SAXS. Time-dependent changes in forward intensity gyration radius suggested existence significant...

Cytochrome P450cam (CYP101) of Pseudomonas putida PpGl in which Arg 112 is substituted by Cys was isolated vitro random mutagenesis the camC gene DNA coding for P450cam. The absorption spectra purified mutant enzyme were similar to those wild type enzyme, but its substrate‐dependent NADH oxidation activity presence putidaredoxin (Pd) and reductase (PdR) extremely low. rate constant electron transfer from reduced Pd heme P450cam, measured on an anaerobic stopped flow apparatus, 1/400 that...

The denaturant-induced equilibrium unfolding transition of equine beta-lactoglobulin was investigated by ultraviolet absorption, fluorescence, and circular dichroism (CD) spectra. An intermediate populates at moderate denaturant concentrations, its CD spectrum is similar to that the molten globule state previously observed for this protein acid pH [Ikeguchi, M., Kato, S., Shimizu, A., Sugai, S. (1997) Proteins: Struct., Funct., Genet. 27, 567-575]. refolding kinetics were also stopped-flow...

The acid-unfolded state of equine β-lactoglobulin was characterized by means circular dichroism, nuclear magnetic resonance, analytical gel-filtration chromatography, and centrifugation. has a substantial secondary structure as shown the far-ultraviolet dichroism spectrum but lacks persistent tertiary packing side chains indicated near-ultraviolet resonance spectra. It is nearly compact native conformation gel filtration sedimentation experiments, it exposed hydrophobic surface its tendency...

and afterwards regarded as a significant source of error in estimating the binding constant Ca" to protein, has been investigated by comparison thermal unfolding curves protein absence presence chelators also measuring NMR spectra chelators, protein-chelator mixtures.The curve large excess each chelator found be identical that chelator, indicating there is essentially no interaction between a-lactalbumin.The results have supported this conclusion, innocuous character these metal-ion buffers...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTContribution of the 6-120 disulfide bond .alpha.-lactalbumin to stabilities its native and molten globule statesMasamichi Ikeguchi, Shintaro Sugai, Motoaki Fujino, Tatsuro Sugawara, Kunihiro KuwajimaCite this: Biochemistry 1992, 31, 50, 12695–12700Publication Date (Print):December 1, 1992Publication History Published online1 May 2002Published inissue 1 December...

Src SH3 is a small all-β-sheet protein composed of single domain. We studied the folding behavior src at various conditions by circular dichroism (CD), fluorescence, and X-ray solution scattering methods. On pathway, an α-helix-rich intermediate appeared not only subzero temperatures but also above 0 °C. The fraction α-helix in kinetically observed ca. 26% based on kinetic CD experiment. revealed that was compact fully packed. analysis implies amplitude burst phase proportional to helical...

The secondary structure formed in disulfide reduced a-lactalbumin is investigated by CD spectrum and compared with that of the folding intermediate intact protein. peptide backbone protein depends strongly on salt concentration contrast to intermediate. It close a random coil absence salt, but it almost same as at high salt. structures both proteins undergo broad unfolding transitions when temperature raised or urea added. less stable against heat urea. These results show bonds are not...

A recombinant bovine alpha-lactalbumin, possessing an additional N-terminal methionyl residue, was expressed in Escherichia coli. In order to address the effects of residue on conformational stability, thermal stability alpha-lactalbumin investigated by measuring temperature-dependence circular dichroism spectra, and it compared with that authentic from milk. The significantly lower than alpha-lactalbumin. enthalpy change unfolding protein found be same as one when at temperature. Therefore,...

For the construction of an overexpression system intracellular 1,2-alpha-mannosidase (EC 3.2.1.113) gene (msdS) from Aspergillus saitoi (now designated phoenicis), N-terminal signal sequence was replaced with that aspergillopepsin I 3.4.23.18) (apnS) signal, one same strains as described previously. Then fused 1, 2-alpha-mannosidase (f-msdS) inserted into NotI site between P-No8142 and T-agdA in plasmid pNAN 8142 (9.5 kbp) thus oryzae expression pNAN-AM1 (11.2 constructed. The f-msdS has...

The urea-induced unfolding of the molten globule state bovine alpha-lactalbumin was investigated by 1H nuclear magnetic resonance. In state, most aromatic resonances deviate from their random coil values, indicating that side chains form some ordered structures in state. When urea concentration increases, are shifted, and deviations values diminished. Because chemical shifts several peptides found to be independent concentration, reflect transition structures. transitions measured individual...

Escherichia coli non-heme-binding ferritin A (EcFtnA) is a spherical cagelike protein that composed of 24 identical subunits. EcFtnA dissociates into 2-mers under acidic conditions and can reassemble the native structure when pH increased. To understand how electrostatic interactions influence assembly reaction, dependence process on ionic strength was investigated. The reaction initiated by stopped-flow mixing acid-dissociated solution high-pH buffer solutions monitored time-resolved...

Ferritin A from Escherichia coli (EcFtnA) is 24-meric protein, which forms spherical cagelike structures called nanocages. The nanocage structure stabilized by the interface around 4-, 3-, and 2-fold symmetric axes. subunit of EcFtnA comprises a four-helix bundle (helices A-D) an additional helix E, 4-fold axis. In this study, we examined contribution three pH-induced dissociation experiments monitored analytical ultracentrifugation small-angle X-ray scattering showed that dimer related...

Abstract The guanidine hydrochloride concentration dependence of the folding and unfolding rate constants a derivative α‐lactalbumin, in which 6‐120 disulfide bond is selectively reduced S‐carboxymethylated, was measured compared with that disulfide‐intact α‐lactalbumin. analyzed on basis two alternative models, intermediate‐controlled model multiple‐pathway model, we had proposed previously. All data supported model. Therefore, molten globule state accumulates at an early stage...