Alpha‐crystallin, a multimeric protein present in the eye lens, is known to have chaperone‐like activity preventing aggregation of enzymes and other crystallins. We studied this towards insulin B chain, induced by reducing interchain disulphide bond with dithiothreitol. At room temperature, there no detectable protection (at 1:1 (w/w) ratio insulin: α‐crystallin) against chain α‐crystallin, whereas it completely prevents at 40°C. monitored temperature dependence α‐crystallin; increases...

A point mutation of a highly conserved arginine residue in αA and αB crystallins was shown to cause autosomal dominant congenital cataract desmin-related myopathy, respectively, humans. To study the structural functional consequences this mutation, human crystallin genes were cloned (Arg-116 Arg-120 crystallin) mutated Cys Gly, by site-directed mutagenesis. The recombinant wild-type mutant proteins expressed Escherichia coli purified. characterized SDS-polyacrylamide gel electrophoresis,...

αB-crystallin, a small heat-shock protein, exhibits molecular chaperone activity. We have studied the effect of αB-crystallin on fibril growth Aβ (amyloid β)-peptides Aβ-(1–40) and Aβ-(1–42). but not BSA or hen egg-white lysozyme, prevented Aβ-(1–40), as revealed by thioflavin T binding, total internal reflection fluorescence microscopy CD spectroscopy. Comparison activity some mutants chimaeric α-crystallins in preventing with their previously reported ability dithiothreitol-induced...

A newly identified 22 kDa protein that interacts with Hsp27 (heat-shock 27) was shown to possess the characteristic α-crystallin domain, hence named Hsp22, and categorized as a member of sHsp (small Hsp) family. Independent studies from different laboratories reported names such H11 kinase, E2IG1 HspB8. We have identified, on basis nucleotide sequence analysis, putative heat-shock factor 1 binding sites upstream Hsp22 translation start site. demonstrate indeed is heat-inducible. show, in...

Refolding of proteins at high concentrations often results in aggregation. To gain insight into the molecular aspects refolding and to improve yield active protein, we have studied lysozyme either from its denatured state or denatured/reduced state. lysozyme, even 1 mg/ml, yields fully enzyme without However, buffer that lacks thiol/disulfide reagents leads Thiol/disulfide redox such as cysteine/cystine reduced/oxidized glutathione facilitate renaturation, with depending on their absolute...

Small heat shock proteins (sHsps) are necessary for several cellular functions and in stress tolerance. Most sHsps oligomers; intersubunit interactions leading to changes oligomeric structure exposure of specific regions may modulate their functioning. Many sHsps, including alpha A- B-crystallin, contain a well conserved SRLFDQFFG sequence motif the N-terminal region. Sequence-based prediction shows that it exhibits helical propensity with amphipathic character, suggesting plays critical...

We have investigated the role of recombinant human alphaA- and alphaB-crystallins in heat-induced inactivation aggregation citrate synthase. Homo-multimers both confer protection against a concentration-dependent manner also prevent aggregation. Interaction crystallins with early unfolding intermediates synthase reduces their partitioning into aggregation-prone intermediates. This appears to result enhanced population that can be reactivated by its substrate, oxaloacetate. Both these...

The small heat shock protein, human HspB2, also known as Myotonic Dystrophy Kinase Binding Protein (MKBP), specifically associates with and activates (DMPK), a serine/threonine protein kinase that plays an important role in maintaining muscle structure function. function of HspB2 are not well understood. We have cloned expressed the E.coli purified it to homogeneity. Far-UV circular dichroic spectrum recombinant shows β-sheet structure. Fluorescence spectroscopic studies show sole tryptophan...

Abstract Proteins, made up of either single or multiple chains, are designed to carry out specific biological functions. We found an interesting example a two-chain protein where administration one its chains leads diametrically opposite outcome than that reported for the full-length protein. Clusterin is highly glycosylated consisting two α- and β-clusterin. have investigated conformational features, cellular localization, lipid accumulation, in vivo effects histological changes upon...

IntroductionDifferent studies have shown the role of micro and macronutrients on cognitive function. Macronutrients been involved in many metabolic activities body including oxidation reduction reactions central nervous system. This involvement system indicates its cognition. The present study is designed to know relation with cognition by using biological samples.Materials methodsA total 337 subjects a mean age 49 participated cross sectional from different parts Kerala state India....

alpha-Crystallin, a multimeric protein present in the eye lens, is shown to have chaperone-like activity preventing thermally induced aggregation of enzymes and other crystallins. We studied rapid refolding alpha-crystallin, compared it with calf lens proteins, namely beta- gamma-crystallins. alpha-Crystallin forms clear solution upon from 8 M urea. The refolded alpha-crystallin has native-like secondary, tertiary, quaternary structures as revealed by circular dichroism fluorescence...

Structural perturbation of alpha-crystallin is shown to enhance its molecular chaperone-like activity in preventing aggregation target proteins. We demonstrate that arginine, a biologically compatible molecule known bind the peptide backbone and negatively charged side-chains, increases calf eye lens as well recombinant human alphaA- alphaB-crystallins. Arginine-induced increase chaperone more pronounced for alphaB-crystallin than alphaA-crystallin. Other guanidinium compounds such...

Several small heat shock proteins contain a well conserved α-crystallin domain, flanked by an N-terminal domain and C-terminal extension, both of which vary in length sequence. The structural functional role the extension proteins, particularly αA- αB-crystallins, is not understood. We have swapped extensions between αB-crystallins generated two novel chimeric αABc αBAc. investigated domain-swapped chimeras for alterations. used thermal non-thermal models protein aggregation found that αB...

Hsp22/HspB8 is a member of the small heat-shock protein family, whose function not yet completely understood. Our immunolocalization studies in human neuroblastoma cell line, SK-N-SH, using confocal microscopy show that significant fraction Hsp22 localized to plasma membrane. We therefore investigated its interactions with lipid vesicles vitro. Intrinsic tryptophan fluorescence quenched presence derived from either bovine brain extract or purified lipids. Time-resolved decrease lifetimes...