RESUMEN
Human milk oligosaccharides, including free oligosaccharides and glycoconjugates, exert a key role in neonatal health and development. Changes in free oligosaccharides of milk from different ethnic groups have been documented. In this study, human milk was collected from Han, Hui, and Tibetan populations in northwest China, and differences in N/O-glycome among these three ethnic groups were systematically compared using online high-performance liquid chromatography-tandem mass spectrometry. Among the 63 detected N-glycans, 35 showed significant differences between the three ethnic groups (p < 0.05). Among the 70 detected O-glycans, four neutral O-glycans and six acidic O-glycans exhibited significant differences among the three ethnic groups (p < 0.05), with six acidic O-glycans reported for the first time. Overall, the extent of milk N/O-glycosylation was higher in the Han population than in the Hui or Tibetan groups. This trend was particularly pronounced for the main sialylated N/O-glycans. Except for sulfated O-glycans, which were higher in the milk from Tibetan mothers, the other types of N/O-glycans were present in similar proportions across all ethnic groups. Understanding the composition of N/O-glycans in human milk can help research on the structure-function relationship of glycans.
Asunto(s)
Calostro , Espectrometría de Masas en Tándem , Femenino , Embarazo , Recién Nacido , Humanos , Espectrometría de Masas en Tándem/métodos , Calostro/química , Etnicidad , Leche Humana/química , Polisacáridos/química , Oligosacáridos/químicaRESUMEN
Self-incompatibility (SI) is a self/non-self discrimination system found widely in angiosperms and, in many species, is controlled by a single polymorphic S-locus. In the Solanaceae, Rosaceae and Plantaginaceae, the S-locus encodes a single S-RNase and a cluster of S-locus F-box (SLF) proteins to control the pistil and pollen expression of SI, respectively. Previous studies have shown that their cytosolic interactions determine their recognition specificity, but the physical force between their interactions remains unclear. In this study, we show that the electrostatic potentials of SLF contribute to the pollen S specificity through a physical mechanism of 'like charges repel and unlike charges attract' between SLFs and S-RNases in Petunia hybrida. Strikingly, the alteration of a single C-terminal amino acid of SLF reversed its surface electrostatic potentials and subsequently the pollen S specificity. Collectively, our results reveal that the electrostatic potentials act as a major physical force between cytosolic SLFs and S-RNases, providing a mechanistic insight into the self/non-self discrimination between cytosolic proteins in angiosperms.
Asunto(s)
Proteínas F-Box/genética , Petunia/genética , Proteínas de Plantas/genética , Polen/genética , Autoincompatibilidad en las Plantas con Flores/genética , Proteínas F-Box/química , Proteínas F-Box/metabolismo , Regulación de la Expresión Génica de las Plantas , Interacciones Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Mutación , Petunia/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Polen/metabolismo , Poliubiquitina/metabolismo , Unión Proteica , Dominios Proteicos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Ribonucleasas/genética , Ribonucleasas/metabolismo , Electricidad EstáticaRESUMEN
CONTEXT: Leonurus artemisia (Lour.) S.Y.Hu (Lamiaceae) (YiMuCao in Chinese) is a traditional Chinese medicine. Leonurus artemisia has been shown to have many pharmacological effects such as increasing uterine contraction amplitude, and tension, but the active components are still unknown. OBJECTIVE: The objective of this study is to determine active components of L. Artemisia that are responsible for the biological activity using HPLC and cell membrane-based system. MATERIALS AND METHODS: The whole L. artemisia ethanol extract and its eight fractions were screened using Sprague-Dawley rat uterus cell membrane chromatography (CMC) combined with the HPLC/MS system. Oxytocin was used to investigate the activity of CMC column. The effect of active components screened from L. artemisia was studied by tension measurement of isolated rat uterine strips in vitro at a dose of 10(-7)-10(-4 )mol/L with oxytocin as a control. RESULTS: The acetone extract showed obvious activity when compared with the eight extracts of L. artemisia. From the acetone extract, in the negative ionization mode, the active compound was identified as genkwanin, with a molecular weight of 283. In vitro pharmacological experiments proved that genkwanin promoted uterine contractions at a dose from 10(-7) to 10(-4 )mol/L. The EC50 value was 4.86 ± 4.21 µmol/L for genkwanin and 4.30 ± 3.65 µmol/L for oxytocin on the contractile amplitude of uterine strips isolated from rats. DISCUSSION AND CONCLUSION: Genkwanin was identified as the active compound in L. artemisia by this method. In vitro pharmacological experiments proved that genkwanin promoted uterine contractions. Genkwanin may be used to uterine inertia and may have an effect on postpartum hemorrhage.