HLDF-6 peptides exhibit neuroprotective effects in the experimental model of preclinical Parkinson's disease.

The mechanisms of the neuroprotective action of the hexapeptides HLDF-6 encoded by the amino acid sequence 41-46 of Human Leukemia Differentiation Factor and its homoserine derivative HLDF-6H were studied in an experimental 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced model of Parkinson's disease (PD). C57Bl/6 mice received two intraperitoneal injections of 18 mg/kg MPTP-HCl, with an interval of 2 hours. MPTP-induced motor dysfunction was assessed using horizontal grid test.

Pharmacokinetics and Molecular Modeling Indicate nAChRα4-Derived Peptide HAEE Goes through the Blood-Brain Barrier.

One of the treatment strategies for Alzheimer's disease (AD) is based on the use of pharmacological agents capable of binding to beta-amyloid (Aβ) and blocking its aggregation in the brain. Previously, we found that intravenous administration of the synthetic tetrapeptide Acetyl-His-Ala-Glu-Glu-Amide (HAEE), which is an analogue of the 35-38 region of the α4 subunit of α4β2 nicotinic acetylcholine receptor and specifically binds to the 11-14 site of Aβ, reduced the development of cerebral amyloidogenesis in a mouse model of AD. In the current study on three types of laboratory animals, we determined the biodistribution and tissue localization patterns of HAEE peptide after single intravenous bolus administration.

Neurotropic peptide HLDF-6-amide reduces age-related decline in sexual activity in old male rats.

Aging is associated with a decline in the erectile capacity and sexual motivation. Emerging new therapy for the treatment of these age-related pathologies in men is the use of the regulatory peptides. We validated the use of HLDF-6-amide (Thr-Gly-Glu-Hse-His-Arg-NH2) as a potential modulator of sexual performance in aged male rats.

Study of the Interaction of Novel Nonprotein Amino Acids with Trypsin by Steady-State Fluorescence Spectroscopy.

The interaction of (2R, 3S)-hydroxyleucine (trypsin inhibitor) and β-hydroxyvaline with trypsin has been studied by the steady-state fluorescence spectroscopy. The analysis of fluorescence spectra has revealed the mechanism of binding of these nonprotein amino acids to trypsin. According to the docking (2R, 3S)-hydroxyleucine form hydrogen bonds with trypsin having little effect on tryptophan and tyrosine residues in enzyme molecule.

Anxiolytic activity of the neuroprotective peptide HLDF-6 and its effects on brain neurotransmitter systems in BALB/c and C57BL/6 mice.

This study is focused on a new amide derivative of the peptide HLDF-6 (Thr-Gly-Glu-Asn-His-Arg). This hexapeptide is a fragment of Human Leukaemia Differentiation Factor (HLDF). It displays a broad range of nootropic and neuroprotective activities.