-
Scientific Reports Oct 2023L-Histidine is an essential amino acid with unique biochemical and physiological properties. Histidinemia is a disease condition caused by the elevated level of...
L-Histidine is an essential amino acid with unique biochemical and physiological properties. Histidinemia is a disease condition caused by the elevated level of L-histidine in our blood. Mutations in the histidase, an enzyme for the breakdown of histidine, is the cause of the rise in histidine concentration. To our knowledge, no research has been done on why a high concentration of histidine causes histidinemia. In this study, we provide a potential explanation why the elevated levels of histidine in the human body causes histidinemia. In this study we have found that L-histidine self-assembled in water to form nano sheet structures at physiological pH and temperature, using 1D H NMR spectroscopy, diffusion ordered spectroscopy (DOSY) and scanning electron microscope (SEM) techniques. The kinetics of self-assembly has been studied using real time NMR spectroscopy. We observed that both the aromatic ring and aliphatic part are equally contributing to the self-assembly of L-histidine. The symptoms of histidinemia, neurological deficits and speech delays, are similar to that of the neurodegenerative diseases caused by the self-assembly of peptides and proteins. We speculate that the self-assembly of L-histidine might be the cause of histidinemia.
Topics: Humans; Histidine; Histidine Ammonia-Lyase; Amino Acid Metabolism, Inborn Errors; Proteins
PubMed: 37838762
DOI: 10.1038/s41598-023-44749-5 -
RSC Advances Jul 2020Histidinemia is a congenital metabolic disorder where the histidine (His) metabolism is blocked, resulting in increased concentrations of His in blood and urine. The...
Histidinemia is a congenital metabolic disorder where the histidine (His) metabolism is blocked, resulting in increased concentrations of His in blood and urine. The disease causes an abnormal development of the patient's nervous system, which leads to many serious illnesses. Therefore, it is very important to diagnose early. In this study, we developed a novel fluorescent nanosensor NaGdF:Yb, Er@SiO-spiropyran (UCNP@SiO-SP). The nanosensor displayed a "turn-off" fluorescence response towards His. When His was mixed with UCNP@SiO-SP, His could specifically bind to SP, which could cause the isomerization of SP. The structure of SP was changed from spiroform into merocyanine form. The luminescence of the sensor was overlapped with the absorption of the merocyanine form. As a result, His will lead to fluorescence quenching of the sensor based on inner filter effects (IFE), which can be used to detect His. Importantly, as the first report of a UCNP@SiO-SP nanosensor for detecting His, this method exhibits good selectivity and anti-interference capability. The detection limit is 4.4 μM. In addition, the amount of His in urine was also measured, suggesting the applicability of this sensor for histidinemia diagnosis.
PubMed: 35515791
DOI: 10.1039/d0ra03711g