Quality assessment of rose tea with different drying methods based on physicochemical properties, HS-SPME-GC-MS, and GC-IMS.

The purpose of this study is to compare the physicochemical properties and volatile flavor compounds of rose tea obtained by the methods of normal temperature drying, hot-air drying (HAD), and vacuum freeze-drying (VFD) and to evaluate the quality of rose tea. The physicochemical results showed that the content of ascorbic acid (VC) and the pH value was the highest in rose tea obtained by HAD. The contents of anthocyanin, proanthocyanidins, and total phenols were highest in rose tea obtained by VFD.

Bridging therapy and direct mechanical thrombectomy in the treatment of cardiogenic cerebral infarction with anterior circulation macrovascular occlusion.

Background: Intravenous thrombolysis is an important treatment for cerebral infarction. However, it is difficult to achieve good results if the patient is complicated with anterior circulation macrovascular occlusion. In addition, the vascular recanalization rate is low, so mechanical thrombectomy, that is, bridging therapy, is needed.

Antitumor effects and molecular mechanisms of action of natural products in ovarian cancer.

Ovarian cancer is a common malignancy and the second leading cause of mortality among females with genital tract cancer. At present, postoperative platinum drugs and paclitaxel-based chemotherapy is the gold standard treatment for ovarian cancer. However, patients who receive this chemotherapy often develop cumulative toxic effects and are prone to chemotherapy resistance.

[Genetic diversity of 6 species in Polygonatum by SSR marker].

Polygonatum is a genus of the perennial herb family Liliaceae, with great potential in food, medicine and other field. In this study, genetic diversity and cluster structure analysis of 6 species in Polygonatum were investigated the molecular marker technique of simple sequence repeat (SSR). A total of 49 SSR makers were used to study genetic diversity and population structure within 60 germplasm resources which obtained from 38 counties and cities in 14 provinces of China.

Molecular overlap in the regulation of SK channels by small molecules and phosphoinositides.

Phosphatidylinositol 4,5-bisphosphate (PIP) directly interacts with the small-conductance Ca-activated K 2-a (SK2-a) channel/calmodulin complex, serving as a critical element in the regulation of channel activity. We report that changes of protein conformation in close proximity to the PIP binding site induced by a small-molecule SK channel modulator, NS309, can effectively enhance the interaction between the protein and PIP to potentiate channel activity. This novel modulation of PIP sensitivity by small-molecule drugs is likely not to be limited in its application to SK channels, representing an intriguing strategy to develop drugs controlling the activity of the large number of PIP-dependent proteins.

Selective phosphorylation modulates the PIP2 sensitivity of the CaM-SK channel complex.

Phosphatidylinositol bisphosphate (PIP2) regulates the activities of many membrane proteins, including ion channels, through direct interactions. However, the affinity of PIP2 is so high for some channel proteins that its physiological role as a modulator has been questioned. Here we show that PIP2 is a key cofactor for activation of small conductance Ca2+-activated potassium channels (SKs) by Ca(2+)-bound calmodulin (CaM).

Unstructured to structured transition of an intrinsically disordered protein peptide in coupling Ca²⁺-sensing and SK channel activation.

Most proteins, such as ion channels, form well-organized 3D structures to carry out their specific functions. A typical voltage-gated potassium channel subunit has six transmembrane segments (S1-S6) to form the voltage-sensing domain and the pore domain. Conformational changes of these domains result in opening of the channel pore.

Identification of the functional binding pocket for compounds targeting small-conductance Ca²⁺-activated potassium channels.

Small- and intermediate-conductance Ca(2+)-activated potassium channels, activated by Ca(2+)-bound calmodulin, have an important role in regulating membrane excitability. These channels are also linked to clinical abnormalities. A tremendous amount of effort has been devoted to developing small molecule compounds targeting these channels.

Characterization of two distinct modes of endophilin in clathrin-mediated endocytosis.

Endophilin, one of the main accessory proteins involved in clathrin-mediated endocytosis, interacts with other endocytic proteins, such as dynamin, by its SH3 domain. We previously reported that voltage-gated Ca(2+) channels are an integral part of the synaptic vesicle (SV) endocytosis machinery through their interaction with endophilin. Formation of the endophilin-channel complex is Ca(2+) dependent.

Structural basis for calmodulin as a dynamic calcium sensor.

Calmodulin is a prototypical and versatile Ca(2+) sensor with EF hands as its high-affinity Ca(2+) binding domains. Calmodulin is present in all eukaryotic cells, mediating Ca(2+)-dependent signaling. Upon binding Ca(2+), calmodulin changes its conformation to form complexes with a diverse array of target proteins.

Structure of the SH3 domain of rat endophilin A2.

The crystal structure of the SH3 domain of rat endophilin A2 has been determined by the multiwavelength anomalous dispersion method and refined at a resolution of 1.70 A to R and R(free) values of 0.196 and 0.

Essential role of the LIM domain in the formation of the PKCepsilon-ENH-N-type Ca2+ channel complex.

A LIM domain is a specialized double-zinc finger motif found in a variety of proteins. LIM domains are thought to function as molecular modules, mediating specific protein-protein interactions in cellular signaling. In a recent study, we have demonstrated that ENH, which has three consecutive LIM domains, acts as an adaptor protein for the formation of a functional PKCepsilon-ENH-N-type Ca2+ channel complex in neurons.

Modulation of the cardiac sodium channel NaV1.5 by Fyn, a Src family tyrosine kinase.

Dynamic modulation of ion channels can produce dramatic alterations of electrical excitability in cardiac myocytes. This study addresses the effects of the Src family tyrosine kinase Fyn on Na(V)1.5 cardiac sodium channels.

A tctex1-Ca2+ channel complex for selective surface expression of Ca2+ channels in neurons.

Voltage-gated Ca(2+) channels (VGCCs) are important in regulating a variety of cellular functions in neurons. It remains poorly understood how VGCCs with different functions are sorted within neurons. Here we show that the t-complex testis-expressed 1 (tctex1) protein, a light-chain subunit of the dynein motor complex, interacts directly and selectively with N- and P/Q-type Ca(2+) channels, but not L-type Ca(2+) channels.

A protein phosphatase 2calpha-Ca2+ channel complex for dephosphorylation of neuronal Ca2+ channels phosphorylated by protein kinase C.

Phosphorylation and dephosphorylation are primary means for rapid regulation of a variety of neuronal functions, such as membrane excitability, neurotransmitter release, and gene expression. Voltage-gated Ca2+ channels are targets for phosphorylation by a variety of second messengers through activation of different types of protein kinases (PKs). Protein phosphatases (PPs), like PKs, are equally important in regulating Ca2+ channels in neurons.

Formation of an endophilin-Ca2+ channel complex is critical for clathrin-mediated synaptic vesicle endocytosis.

A tight balance between synaptic vesicle exocytosis and endocytosis is fundamental to maintaining synaptic structure and function. Calcium influx through voltage-gated Ca2+ channels is crucial in regulating synaptic vesicle exocytosis. However, much less is known about how Ca2+ regulates vesicle endocytosis or how the endocytic machinery becomes enriched at the nerve terminal.

A PKC epsilon-ENH-channel complex specifically modulates N-type Ca2+ channels.

Multiple protein kinase C (PKC) isozymes are present in neurons, where they regulate a variety of cellular functions. Due to the lack of specific PKC isozyme inhibitors, it remains unknown how PKC acts on its selective target(s) and achieves its specific actions. Here we show that a PKC binding protein, enigma homolog (ENH), interacts specifically with both PKCepsilon and N-type Ca2+ channels, forming a PKCepsilon-ENH-Ca2+ channel macromolecular complex.