China 
Africa 
Explore chapters and articles related to this topic
Arsenals of Pharmacotherapeutically Active Proteins and Peptides: Old Wine in a New Bottle
Published in Debarshi Kar Mahapatra, Swati Gokul Talele, Tatiana G. Volova, A. K. Haghi, Biologically Active Natural Products, 2020
Tryptophan is precursor of amino acid for serotonin (5-hydroxytryptamine). Serotonin is responsible for appetitive, emotional, motor, cognitive, and autonomic behaviors. Serotonin is also involved in the neuroendocrine function and circadian clock rhythm. It also functions as precursor of melatonin, which possess sedative and hypnotic properties [31, 32]. Tryptophan is also involved synthesis of molecules like niacin, tryptamine, and kynurenine. Dopamine, norepinephrine, and epinephrine are tyrosine derivatives. These tyrosine derivatives are neurotransmitters mediating various function of the nervous system [33]. The structures of various amino acid derivatives are shown in Figure 2.16.
Tryptophan capped gold-aryl nanoparticles for energy transfer study with SARS-CoV-2 spike proteins
Published in Soft Materials, 2022
Javad B. M. Parambath, Sofian M. Kanan, Ahmed A. Mohamed
Coronavirus disease 2019 (COVID-19) vastly spread causing a global pandemic which has been triggered by respiratory syndrome coronavirus 2 (SARS-CoV-2).[1] Ongoing research on this severe acute respiratory disease focuses on the viral spike protein (S-proteins) for developing reliable detection methods, therapies, and vaccines. The binding and structural features of these proteins are critical in host cell interaction.[2] Understanding the pathophysiology of SARS-CoV-2 is still under investigation. Recent studies have shown the role of tryptophan metabolism in differential regulation of responses to SARS-CoV-2.[3,4] Studies have shown the cytokine storm leading to acute respiratory distress has a key role in tryptophan metabolism, which regulates the immune system through the kynurenine pathway.[5] Therefore, the role of tryptophan in SARS-CoV-2 infection is critical and might be a valuable biomarker for therapeutic interventions.
Structural and functional analysis of broad pH and thermal stable protease from Penicillium aurantiogriseum URM 4622
Published in Preparative Biochemistry & Biotechnology, 2022
José Manoel Wanderley Duarte Neto, Jônatas de Carvalho Silva, Flávia Sousa, Odete Sofia Lopes Gonçalves, Maria Carolina de Albuquerque Wanderley, Bruno Sarmento, Carolina de Albuquerque Lima, Maria Teresa Neves-Petersen, Ana Lúcia Figueiredo Porto
Figure 3 shows the photoproducts formed as a consequence of continuous 280 nm illumination at different pH values during the thermal treatment. N-formylkynurenine (λexmax = 322 nm), kynurenine (λexmax = 365 nm) and dityrosine (λexmax = 315 nm) formation can be monitored upon excitation at 320 nm. Excitation at 360 nm allows for monitoring the kynurenine formation. N-formylkynurenine still absorbs at 360 nm even though the absorption peak is registered at 322 nm. The same is observed for kynurenine, where the maximum absorption peak is registered at 365 nm but still absorbs at 320 nm.[12] In Figure 3A are depicted N-formylkynurenine, kynurenine, dityrosine fluorescence spectra upon excitation at 320 nm (λemission 360–530 nm) and in Figure 3B are depicted N-formylkynurenine and kynurenine fluorescence spectra upon excitation at 360 nm (λemission 420–530 nm). N-formylkynurenine, kynurenine, dityrosine are reported to show a maximum fluorescence emission peak at 434, 480, and 410 nm, respectively.[12–14,29,30]