A detailed circular dichroic (CD) study of the conformational flexibility of the melanin-concentrating hormone core [MCH(5-14)] is reported. Variable pH (2-10) and temperature (-80 degrees to +80 degrees C) in aqueous media reveal that CD contributions from tyrosine, disulphide bridge and the amide backbone can be discriminated. Only below -10 degrees C does a preferred -S-S-conformation (P chirality, dihedral angle phi = 90 +/- 10 degrees) dominate. The amide backbone CD contribution varies over all temperatures (-80 degrees to +80 degrees C) providing evidence for a type-II beta-turn at low temperatures, with the emergence of a type-I beta-turn at higher temperatures. Tyrosine exhibits a special behaviour at pH 7. These conclusions are in broad agreement with published NMR studies. Nevertheless, the MCH(5-14) core is seen to be conformationally flexible in aqueous solution at ambient temperatures. Conformation differences are observed in a non-aqueous environment.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1111/j.1432-1033.1992.tb16897.x | DOI Listing |
ACS Chem Neurosci
January 2025
School of Pharmacy, University of Wisconsin─Madison, Madison, Wisconsin 53705, United States.
Addiction to psychostimulants, including cocaine, causes widespread morbidity and mortality and is a major threat to global public health. Currently, no pharmacotherapies can successfully treat psychostimulant addiction. The neuroactive effects of cocaine and other psychostimulants have been studied extensively with respect to their modulation of monoamine systems (particularly dopamine); effects on neuropeptide systems have received less attention.
View Article and Find Full Text PDFFront Nutr
December 2024
Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong, China.
Objective: The ventral tegmental area (VTA), a pivotal hub in the brain's reward circuitry, receives inputs from the lateral hypothalamic area (LHA). However, it remains unclear whether melanin-concentrating hormone (MCH) and orexin-A (OX-A) neurons in the LHA exert individual or cooperative influence on palatable food consumption in the VTA. This study aims to investigate the modulatory role of MCH and OX-A in hedonic feeding within the VTA of high-fat diet (HFD) mice.
View Article and Find Full Text PDFJ Neurosci
January 2025
Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI USA
Regulation of food intake and energy balance is critical to survival. Hunger develops as a response to energy deficit and drives food-seeking and consumption. However, motivations to eat are varied in nature, and promoted by factors other than energy deficit.
View Article and Find Full Text PDFBMC Anesthesiol
December 2024
Department of Anesthesiology, Cangzhou Central Hospital, Cangzhou, Hebei, China.
Objectives: To explore the effect of mild cognitive impairment (MCI) and MCI with sleep disorders on the potency of sevoflurane anesthesia in the elderly.
Design: Prospective study methods. Dixon up-and-down methods.
Sleep Sci
December 2024
Departamento de Psicobiologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
Melanin-concentrating hormone (MCH) and hypocretins (Hcrt) 1 and 2 are neuropeptides synthesized in the lateral hypothalamic area by neurons that are critical in the regulation of sleep and wakefulness. Their receptors are located in the same cerebral regions, including the frontal cortex and hippocampus. The present study aimed to assess whether 96 hours of paradoxical sleep deprivation alters the functioning of the MCH and hypocretin systems.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!