The essence of modern nanotechnology is manifested in the formation of well-ordered nanostructures by a process of self-association. Peptides are among the most useful building blocks for organic bionanostructures such as nanotubes, nanospheres, nanotapes, nanofibrils, and other different ordered structures at the nanoscale. Peptides are biocompatible, chemically diverse, and much more stable and can be readily synthesized on a large scale. Also, they have diverse application in biosensors, tissue engineering, drug delivery, etc. Here, we report a short cystine-based dipeptide, which spontaneously self-associates to form straight, unbranched nanotubes. Such self-assembled nanobiomaterials provide a novel possibility of designing new functional biomaterials with potential applications in nanobiotechnology. The formation of nanotubes in solution state has been demonstrated by atomic force microscopy and scanning electron microscopy. Infrared absorption and circular dichroism demonstrated the intermolecular b-sheet-like backbone hydrogen bonding in juxtaposing and stacking of aromatic side chains.

In view to better understand the interactions of aminoacids and peptides with metallic cations, in the isolated state, the model system glycylglycine–Zn2+has been theoretically studied.Structures and energetic of complexes between glycylglycine dipeptide and zinc cation were investigated applying density functional theory (DFT). Zn2+cation was allowed to interact with different sites of glycylglycine and six stable isomers were obtained. Calculation for six different glycylglycine-Zn2+isomers were performed at BLYP and B3LYP level of theory using 6-31G* and 6-31G** basis sets. Relative energy calculations at different levels indicated that the most stable complex holds the structure, in which zinc cations are bound to the oxygen sites of carbonyl groups and the dipeptide of glycylglycine which acts as a bidentate ligand that has a structure of six-membered ring. Vibration frequency of most stable isomer is calculated by BLYP level and enthalpy, entropy and Gibbs energy of reaction was obtained.

In the present work, an extensive theoretical calculation study on Histidine-Histidine dipeptide in gas phase is done by using DFT method with Gaussian 98 program. Through investigations on the molecular geometries of this molecule it is found that there is six rings in the molecules not two rings. The presence of four intramolecular hydrogen bonds is responsible for the formation of additional four rings besides two imidazole rings which gives more stability to the molecule. The quantum theory of atoms in molecules (QTAIM) proves these strong intramolecular hydrogen bonds in the title dipeptide.

peptides have shown Promising effect as pharmaceutics with the potential to treat a wide variety of diseases. Peptides are mostly synthesized by biological technology or chemical methods. Solution phasepeptide synthesis (SPS) and solid phase peptide synthesis (SPPS) are two major chemical techniques for peptidesproduction.In this research, the synthesis of dipeptde (b -alanine- L -histidine) wasexaminedby the both SPS and SPPS methods. The solution phase synthesizeswasdonebyN -phthalic anhydride as a protective group andthe solid phase using standardtert-Butyloxycarbonyl (BOC) and Fluorenylmethyloxycarbonylchloride (Fmoc).Inthe both methods, themicrowave was assisted in different steps. The molecular structure of the dipeptide (b -alanine- L -histidine) wasdefined using different spectrometrymethods such as: UV-Vis, FT-IR, 1HNMR and LC-Massanalysis.

Introduction: Alzheimer disease (AD) is a progressive neurodegenerative disorder that is identified by the gradual decline in memory and cognitive function. It is classified by the deposition of Aβ plaques, the build-up of intracellular neurofibrillary tangle (NFT), and neuron loss. Neurotrophic factors play a critical role in the treatment of AD. However, utilizing such neurotrophins has encountered certain difficulties and side effects. Novel technological advancements prioritize innovative dipeptide usage, which offers fewer side effects.  Methods: The present study endeavors to analyze the compound hexamethylenediamide bis-(N-monosuccinyl-glutamyl-lysine) (lab name: H-MGL), a newly discovered neurotrophin mimetic dipeptide, to alleviate memory impairment in an intracerebroventricular single dose streptozotocin (STZ)-induced Alzheimer model in rats. We arranged 4 groups: Sham and groups receiving STZ and STZ + H-MGL (1 and 2 mg/kg). The H-MGL was administered consecutively for 14 days following the STZ injection. Then, the Morris water maze test was performed. Results: The findings suggest that administration of STZ caused a significantly increment in mean escape latency and mean traveled distance in acquisition days. H-MGL at a 1 mg/kg dosage failed to yield any notable improvement in rats compared to STZ. By contrast, 2 mg/kg of H-MGL dosage led to a significant decrease in the latency to first platform crossing and frequency of platform crossings.  Conclusion: Consequently, the findings above have engendered the notion that H-MGL partially ameliorates cognitive impairment, so it may hold promise for having low side effects to alleviate cognitive deficits in AD or potentially decrease the symptoms associated with its progression.