Solution structure of humanin, a peptide against Alzheimer’s disease-related neurotoxicity☆
Section snippets
Materials and methods
Preparation of humanin. Humanin was prepared by Fmoc-solid phase synthesis [16] on an in-house prepared o-Cl-trityl-amidomethyl polystyrene resin. The peptide was purified to 95% with semi-preparative RP-HPLC and suitably characterized.
CD spectropolarimetry. CD spectra of humanin in the range 250–180 nm were recorded on a Jasco J715 spectropolarimeter using 1 mm quartz cells, 1 nm bandwidth, 0.2 nm resolution, 1 s response, and an average of 8 scans for each spectrum. The temperature of the samples
CD study
The CD spectra of humanin (0.19 mg/mL, 0.07 mM) in aqueous solutions in the presence of various concentrations of TFE at 25 °C are shown in Fig. 1A. In the absence of TFE, the CD spectrum shows strong negative dichroism below 200 nm, indicative of a small degree of ordering in the peptide [26]. On addition of TFE, changes diagnostic of conformational equilibrium between unordered structures and helical conformations of humanin in solution take place in the CD spectra [27]. The mean residue
Discussion
The potent in vitro neuroprotective activity of humanin against the insults of the AD-related genes and the neurotoxic β-amyloid peptide has spurred new hopes for the development of a pharmaceutical therapy against AD. To establish therapeutic strategies, as well as to clarify the mechanism of AD pathogenesis, the mode of humanin action must be understood. Our CD, NMR, and 3D comparative modeling data demonstrate that in aqueous solution humanin possesses essentially no stable secondary
Acknowledgments
M. Pelecanou wishes to acknowledge financial support by the National Bank of Greece and C. Zikos wishes to acknowledge a financial grant offered by Biomedica Life Sciences S.A.
References (43)
Alzheimer’s disease: Its proteins and genes
Cell
(1988)Mechanism of neuronal degeneration in Alzheimer’s disease
Neuron
(1996)- et al.
Genes and susceptible loci of Alzheimer’s disease
Brain Res. Bull.
(1999) A new paradigm for neurotoxicity by FAD mutants of β APP: A signalling abnormality
Neurobiol. Aging
(1998)- et al.
Mechanisms of neuroprotection by novel rescue factor Humanin from Swedish mutant amyloid precursor protein
Biochem. Biophys. Res. Commun.
(2001) - et al.
Identification of essential amino acids in Humanin, a neuroprotective factor against Alzheimer’s disease-relevant insults
Peptides
(2003) - et al.
NPS@: Network protein sequence analysis
TIB
(2000) - et al.
Modulation of host signalling by a bacterial mimic structure of the salmonella effector SPTP bound to RAC1
Mol. Cell
(2000) - et al.
Circular dichroism and optical rotatory dispersion of proteins and polypeptides
Methods Enzymol.
(1973) - et al.
Folding of immunogenic peptide fragments of proteins in water solution. II. The nascent helix
J. Mol. Biol.
(1988)
N-Formylated humanin activates both formyl peptide receptor-like 1 and 2
Biochem. Biophys. Res. Commun.
Snapshots of membrane-translocating proteins
Trends Cell Biol.
Thermodynamics of lipid–peptide interactions
Biochim. Biophys. Acta
Therapeutic strategies for Alzheimer’s disease
Nat. Rev., Drug Discov.
Alzheimer’s disease: A disorder of cortical cholinergic innervation
Science
Alzheimer’s disease: The amyloid cascade hypothesis
Science
The genetics of Alzheimer disease
Arch. Neurol.
A rescue factor abolishing neuronal cell death by a wide spectrum of familial Alzheimer’s disease genes and Aβ
Proc. Natl. Acad. Sci. USA
Detailed characterization of neuroprotection by a rescue factor Humanin against various Alzheimer’s disease relevant insults
J. Neurosci.
Humanin rescues human cerebrovascular smooth muscle cells from Aβ-induced toxicity
J. Neurochem.
Death and survival of neuronal cells exposed to Alzheimer’ s insults
J. Neurosci. Res.
Cited by (51)
Humanin and Alzheimer's disease: The beginning of a new field
2022, Biochimica et Biophysica Acta - General SubjectsHumanin: A mitochondrial-derived peptide in the treatment of apoptosis-related diseases
2021, Life SciencesCitation Excerpt :For instance, Ser at 7th and Leu at 9th position successfully prevents self-aggregation in dimer or oligomer of HN-polypeptide chain during neuroprotective function [17]. The circular dichroism and NMR studies of synthetic HN in 2, 2, 2-trifluoroethanol (TFE; 30%) and aqueous solution revealed that HN exists in helical like structure with Gly5 to Leu18 sequence order spanning in 30% TFE solution and adopts unstructured confirmation in equilibrium with a turn-like structure in an aqueous solution that provides nascent helix with Gly5-leu10 and Glu15-Leu18 sequence order spanning [42]. Another NMR study of HN in aqueous solution reported that Leu9 and Leu10 are proximal to Phe6 aromatic ring which helped in forming a hydrophobic binding and broken by substitution of Leu10 either by acidic or basic residue [43].
Extension of the Quantum Universal Exchange Language to precision medicine and drug lead discovery. Preliminary example studies using the mitochondrial genome
2020, Computers in Biology and MedicineCitation Excerpt :For humanin and TPLTSGLLLLTWQKLAPISIMY,shown along with the alignment, the prediction is.Image 35 The CECEC motif might suggest the e-sections pairing to form a hairpin pleated sheet, but this is not the experimental evidence [46]. Leucine L is a strong a-helix former so the helical conformation on binding to a target is expected, of which nonpolar solvents are models (albeit lacking specificity).
A benchmark of optimally folded protein structures using integer programming and the 3D-HP-SC model
2020, Computational Biology and ChemistryHumanin induces conformational changes in the apoptosis regulator BAX and sequesters it into fibers, preventing mitochondrial outer-membrane permeabilization
2019, Journal of Biological ChemistryCitation Excerpt :Multiple reports describe HN as generally disordered in aqueous solutions but gaining α-helical structure in lipophilic environments. Conformational dynamics between the disordered and α-helical states can change with HN mutations (49–58). Some β-strand and β-sheet forming activity has also been described for HN with the C8A mutation disrupting this process, but C8A HN still forms disordered aggregations that are reversible with the monomer state (59).
Solution NMR structure and inhibitory effect against amyloid-β fibrillation of Humanin containing a D-isomerized serine residue
2016, Biochemical and Biophysical Research CommunicationsCitation Excerpt :Tertiary structures of HN wild-type and HN S14G in a 2,2,2-trifluoroethanol (TFE)/water mixtures have previously been revealed by Benaki and his co-workers using solution nuclear magnetic resonance (NMR) techniques [9,10]. Both HN wild-type and HN S14G form straight helical structures even though they are predominantly disordered in alcohol-free water [9–11]. In the case of HN S14G it has been reported that the C-terminal site of the helical structure was slightly disordered relative to that of the HN wild-type [10].
- ☆
Humanin structure has been deposited with the RCSB Protein Data Bank, File Name: 1Y32.