α-synuclein蛋白与A-β肽和β-synuclein蛋白相互作用位点的预测

α-synuclein蛋白的异常聚集是引起帕金森病的重要因素.实验研究发现,α-synuclein蛋白能与多个蛋白相互作用.在相互作用的蛋白质中,有的可以促进α-synuclein的异常聚集,如A-β肽;有的可以抑制α-synuclein的异常聚集,如β-synuclein蛋白,但促进或抑制α-synuclein异常聚集的机理并不明确.利用SYBYL和AUTODOK软件模拟α-synuclein蛋白与A-β肽和β-synuclein的相互作用,找到其相互作用位点,为进一步研究α-synuclein蛋白的异常聚集提供理论依据.     

点击化学用于生物分子标记的研究进展（英文）

自1999年Barry Sharpless提出点击化学的概念以来,其得到极大的关注和发展。主要介绍了点击化学的定义和分类,其中Cu(I)催化下炔基与叠氮可形成稳定的1,2,3-3氮唑化合物,这类反应的应用最为广泛。它在标记生物大分子方面的应用主要从4个方面展开,包括标记多肽和蛋白,DNA和RNA,细胞中的酯质和病毒表面。     

Peptidergic innervation of the temporomandibular disk in the rat

Summary The peptidergic innervation of the temporomandibular disk was investigated in the postnatal young rat by using an indirect immunofluorescence method. Calcitonin gene-related peptide-containing nerve fibers were located around the blood vessels and terminated as free nerve endings in the disk. These nerve fibers may be of a sensory nature.     

Influence of PrP 106―126 on expression of laminin and fibronectin in astrocyte

Astrogliosis is a hallmark of prion disease, but the metabolic alterations of astrocytes remain poorly documented. A synthetic peptide corresponding to amino acid 106-126 of the human prion protein （PrP） has been shown to be toxic to neurons. In this study, the effects of PrP 106-126 on astrocytes were investigated in vitro. The proliferation of astrocytes was significantly （P 〈 0.05） increased when grown in media conditioned with PrP 106-126 （80 μmol/L） from microglia. The expression of laminin （LN） and fibronectin （FN） was examined at both mRNA and protein levels. The results showed that exposure of astrocytes to PrP 106-126 enhanced the expression of LN and FN. The increase of FN in astrocyte cultures required cytokines previously released by activated microglia. This study reveals the expression of LN and FN affected by PrP106-126.     

肽的等电点计算方法

肽是两性电解质,肽的等电点和氨基酸一样可根据它各自解离基团的ＰＫ值求得。即肽的等电点为它的两性离子两侧的ＰＫ的平均值。     

Novel and sensitive noncompetitive enzyme immunoassay for kassinin in rat plasma

Summary A novel and sensitive noncompetitive enzyme immunoassay for kassinin is described. Kassinin was biotinylated using sulfosuccinimidyl-6-(biotinamido)hexanoate. The biotinylated kassinin was trapped on antikassinin IgG-coated polystyrene balls and, after washing to eliminate other biotinylated substances, was eluted with HCl. The biotinylated kassinin eluted was reacted with anti-kassinin Fab'-peroxidase conjugate and trapped onto streptavidin-coated polystyrene balls. Peroxidase activity bound to the polystyrene balls was assayed by fluorimetry. The detection limit of kassinin was 0.13 pg (0.1 fmol)/tube or 0.065 g/l of rat plasma, which was 750-fold or 15-fold lower than that for competitive radioimmunoassay.     

Antagonism of V2-receptor effect of antidiuretic hormone by atrial natriuretic peptide in man

Summary Human -atrial natriuretic peptide (h-ANP) makes the urine of dehydrated volunteers hypotonic to plasma despite high circulating concentrations of antidiuretic hormone. Urinary dilution with h-ANP also occurs in subjects receiving indomethacin. Therefore, h-ANP antagonises effects of antidiuretic hormone on distal tubular V₂-receptors in man, probably without involving prostaglandins.     

Stomatal guard cell responses to kinetin and natriuretic peptides are cGMP-dependent

Immunological evidence suggests that plants contain natriuretic peptides (NPs) and furthermore (3- [¹²⁵I]iodotyrosol²⁸) rat atrial NP (rANP) binds specifically to plant membranes. rANP and immunoaffinity-purified plant NP analogues also promote concentration-dependent stomatal opening. Here we report that kinetin, a synthetic cytokinin, and rANP induce stomatal opening in Tradescantia albiflora and that the effect of rANP is critically dependent on the secondary structure of the peptide hormone. The native circular molecule is active, whereas the linearized molecule shows no biological activity. Furthermore, kinetin- and rANP-induced stomatal opening is reversibly inhibited by two in hibitors of guanylate cyclase, LY 83583 and methylene blue. Stomatal opening is also induced in a concentration-dependent manner by the cell-permeant cyclic guanosine-3′,5′-monophosphate (cGMP) analogue 8-Br-cGMP, and this effect is prevented by the stomatal closure promoting plant hormone abscisic acid (ABA). We conclude that in guard cells kinetin and rANP pathways operate via guanylate cyclase upregulation, and we propose that ABA-induced closure is not cGMP-dependent. Received 1 October 1997; received after revision 2 December 1997; accepted 6 January 1998     

家蝇抗菌肽的分离纯化及性质研究

采用阳离子交换法,分别以pH5.1的乙酸铵和pH6.6的甲酸铵作缓冲液进行2次离子梯度洗脱,从家蝇成虫血淋巴中分离得到1种抗菌肽CM-Ⅲ.SDS-PAGE电泳显示为1条带,分子量约为10000μ,耐受高温的能力强,100℃处理10 min仍有活性.它对革兰氏阳性菌(金黄色葡萄球菌、白葡萄球菌)和阴性菌(绿脓假单胞菌、大肠杆菌、肠炎沙门氏菌)都有抗性,其中对致病性金黄色葡萄球菌6538P抑菌活力最强.CM-Ⅲ对血细胞没有凝聚作用.其抗菌机理尚待进一步研究.