PH结构域与细胞方向感觉

PH（pleckstrin homology）结构域与细胞方向感觉关系密切,目前已发现,PH结构域存在于60多种蛋白质中,这些蛋白质能与趋化细胞胞膜表面的相关结合位点结合,进而激发信号转导的下游事件.这种结合有以下特点：a.迅速而短暂;b.只与外界环境中两点间浓度梯度差相关,据此提出了“空间模式”;c.改变趋化剂的位置时,结合位点在胞膜上的分布也随之改变,由此提出了“时间模式”.深入而全面地探讨各种PH结构域及其结合位点在细胞方向感觉中的作用,对于细胞方向感觉的研究具有巨大的推动作用和深远的理论意义.     

膜结合鸟苷酸激酶蛋白质家族的结构与功能

MAGUKs蛋白家族成员位于细胞表面,通过其PDZ、SH₃、GK结构域调节离子通道受体的聚集,构建细胞骨架,参与信号转导,调控细胞周期进程,并与机体神经发育密切相关.     

Crystal structure of a novel ATPase RadD from Escherichia coli

The helicase superfamily 2 (SF2) proteins are involved in essentially every step in DNA and RNA metabolism. The radD (yejH) gene, which belongs to SF2, plays an important role in DNA repair. The RadD protein includes all seven conserved SF2 motifs and has shown ATPase activity. Here, we first reported the structure of RadD from Escherichia coli containing two RecA-like domains, a zinc finger motif, and a C-terminal domain. Based on the structure of RadD and other SF2 proteins, we then built a model of the RedD-ATP complex.     

Identification of Novel Kinases of Tau Using Fluorescence Complementation Mass Spectrometry (FCMS)

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Structures and target RNA preferences of the RNA-binding protein family of IGF2BPs: An overview

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Cyclic nucleotide selectivity of protein kinase G isozymes

The intrinsic activity of the C‐terminal catalytic (C) domain of cyclic guanosine monophosphate (cGMP)‐dependent protein kinases (PKG) is inhibited by interactions with the N‐terminal regulatory (R) domain. Selective binding of cGMP to cyclic nucleotide binding (CNB) domains within the R‐domain disrupts the inhibitory R–C interaction, leading to the release and activation of the C‐domain. Affinity measurements of mammalian and plasmodium PKG CNB domains reveal different degrees of cyclic nucleotide affinity and selectivity; the CNB domains adjacent to the C‐domain are more cGMP selective and therefore critical for cGMP‐dependent activation. Crystal structures of isolated CNB domains in the presence and absence of cyclic nucleotides reveal isozyme‐specific contacts that explain cyclic nucleotide selectivity and conformational changes that accompany CNB. Crystal structures of tandem CNB domains identify two types of CNB‐mediated dimeric contacts that indicate cGMP‐driven reorganization of domain–domain interfaces that include large conformational changes. Here, we review the available structural and functional information of PKG CNB domains that further advance our understanding of cGMP mediated regulation and activation of PKG isozymes.     

Improving the pharmacokinetic properties of biologics by fusion to an anti-HSA shark VNAR domain

Advances in recombinant antibody technology and protein engineering have provided the opportunity to reduce antibodies to their smallest binding domain components and have concomitantly driven the requirement for devising strategies to increase serum half-life to optimise drug exposure, thereby increasing therapeutic efficacy. In this study, we adopted an immunization route to raise picomolar affinity shark immunoglobulin new antigen receptors (IgNARs) to target human serum albumin (HSA). From our model shark species, Squalus acanthias, a phage display library encompassing the variable binding domain of IgNAR (VNAR) was constructed, screened against target, and positive clones were characterized for affinity and specificity. N-terminal and C-terminal molecular fusions of our lead hit in complex with a naïve VNAR domain were expressed, purified and exhibited the retention of high affinity binding to HSA, but also cross-selectivity to mouse, rat and monkey serum albumin both in vitro and in vivo. Furthermore, the naïve VNAR had enhanced pharmacokinetic (PK) characteristics in both N- and C-terminal orientations and when tested as a three domain construct with naïve VNAR flanking the HSA binding domain at both the N and C termini. Molecules derived from this platform technology also demonstrated the potential for clinical utility by being available via the subcutaneous route of delivery. This study thus demonstrates the first in vivo functional efficacy of a VNAR binding domain with the ability to enhance PK properties and support delivery of multifunctional therapies.