A covalently constrained congener of the Saccharomyces cerevisiae tridecapeptide mating pheromone is an agonist

An analog of alpha-factor, the Saccharomyces cerevisiae tridecapeptide mating pheromone (Trp-His-Trp-Leu-Gln-Leu-Lys-Pro-Gly-Gln-Pro-Met-Tyr), in which the side chains of Lys7 and Gln10 were covalently linked, was synthesized using solid phase methodologies. The yield of the purified cyclic analog cyclo7,10[Nle12]alpha-factor was 30%, and its structure was verified by amino acid analysis, peptide sequencing, fast atom bombardment-mass spectrometry, and proton nuclear magnetic resonance spectroscopy. Cyclo7,10[Nle12]alpha-factor caused growth arrest and morphological alterations in S. cerevisiae MATa cells qualitatively identical to those induced by linear pheromone and was one-fourth to one-twentieth as active as the linear alpha-factor depending upon the S. cerevisiae strain tested. Consistent with the relative activities of the linear and cyclic peptides, binding competition studies indicated that cyclo7,10[Nle12]alpha-factor had approximately 20-40-fold less affinity for the alpha-factor receptor. Hydrolysis of the cyclic peptide by the target cells did not lead to opening of the ring and was less rapid than that of linear alpha-factor. The alpha-factor antagonist des-Trp1-[Ala3,Nle12]alpha-factor reversed the activity of the cyclic analog, and cyclo7,10[Nle12]alpha-factor was not active at the restrictive temperature in a temperature-sensitive receptor mutant. These results support the conclusion that the cyclic alpha-factor occupies the same binding site within the receptor as is occupied by the natural pheromone. The cyclic alpha-factor represents a rare example of an agonist among covalently constrained congeners of small linear peptide messengers.     

Antinociceptive effects of [D-Ala2]deltorphin II, a highly selective delta agonist in vivo

The present study has characterized the antinociceptive actions of [D-Ala2]deltorphin II following intracerebroventricular (i.c.v.) administration in the mouse tail-flick test. [D-Ala2]deltorphin II produced dose- and time-related antinociception, with maximal effects at +10 min and significant antinociception which lasted for 40-60 min. [D-Ala2]deltorphin II was 13-fold more potent than i.c.v. [D-Pen2, D-Pen5]enkephalin (DPDPE), a second highly selective delta agonist, and approximately equipotent with i.c.v. morphine in producing antinociception. The antinociceptive effects of i.c.v. [D-Ala2]deltorphin II and DPDPE, but not those of morphine, were antagonized by the selective delta antagonist, ICI 174,864. In contrast, pretreatment with the non-equilibrium mu antagonist, beta-funaltrexamine blocked morphine antinociception, but failed to antagonize [D-Ala2]deltorphin II and DPDPE antinociception. These data indicate that [D-Ala2]deltorphin II produced its antinociceptive effects at a supraspinal delta receptor. [D-Ala2]deltorphin II appears to be the most appropriate delta opioid agonist currently available for studies in vivo and support the involvement of delta receptors in supraspinal antinociception.     

4D和4R对小麦三种同工酶合成的影响

利用聚丙烯酰胺凝胶电泳对小麦品种天选15号、天选15号—4D缺体,黑麦品种德国白粒及利用“缺体回交法”培育的小麦(4D)一黑麦(4R)异代换系幼苗的过氧化物酶同工酶、细胞色素氧化酶同工酶及酯酶同工酶进行了研究,结果表明4D染色体对小麦的一种过氧化物酶同工酶和一种细胞色素氧化酶同工酶量的合成具有控制作用,在小麦4D缺体的遗传背景下,黑麦4R染色体能够补偿由于4D缺失引起的这两种同工酶合成降低的效应。4D对小麦幼苗期酯酶同工酶的合成没有明显的作用,4R在小麦4D缺体遗传背景下对酯酶同工酶的合成也没有明显的影响     

草莓花药培养获得无病毒植株的技术研究

以花粉发育为单核期的花药接种,在MS附加IAA 4ppm、K 2ppm、BA 2ppm的培养基上诱导愈伤组织,并可直接分化出“沙尔普斯”、“红岗利德”、“春香”3个品种的花药植株。稍加调整附加激素成分和浓度,可在“索非亚”、“宝交早生”、“戈雷拉”、“红衣”、“丽红”等品种的花药上直接经愈伤组织分化出植株。其中有“沙尔普斯”、“红岗利德”、“春香”、“宝交早生”、“索非亚”等5个品种的花药植株经过病毒检测确认不带SMoV、SCrV、SMYEV和SVBV4种病毒。对无病毒植株进行了田间对比试验,植株生长势和果实产量都明显超过对照品种。     

裂叶苣荬菜的研究

本文对裂叶苣荬菜(Sonchus arvensis L)进行了初步研究。考察了它的植物生态特征和分布环境,预试了化学成分并进行了临床病例观察。为裂叶苣荬菜以其本名作为治疗肝炎的草药入药提供了可靠的依据。     

皮层第二体感区下行活动对尾核神经元伤害性反应的影响

本实验用清醒麻痹的家猫观察到,皮层第二体感区(SⅡ区)的下行活动对尾核痛相关单位的自发放电和伤害性反应均有影响。在35个痛相关单位中,刺激SⅡ区后,62.7％的自发放电受到影响(p<0.05)。在72个痛相关单位中,刺激SⅡ区后,77.8％的伤害性反应受到抑制(p<0.01),其中抑制痛兴奋单位的伤害性反应最为明显。而用利多卡因局部阻滞SⅡ区后,33个痛相关单位中,51.5％的伤害性反应增强(p<0.01)。本结果提示:(1)SⅡ区的下行活动不仅对尾核痛相关单位的自发活动有影响,而且对痛相关单位的伤害性反应有以抑制为主的下行性调制作用。(2)在正常机能状态下,SⅡ区对伤害性信息向尾核的传递有一定的紧张性的下行性抑制作用。     

Cytogenetic characterization of 20 lymphoblastoid lines derived from human individuals differing in bleomycin sensitivity

Summary Forty lymphoblastoid (lymphoid) lines were established from 42 volunteer blood donors, including healthy individuals and patients with head and neck carcinomas. Each peripheral blood sample was split into two portions, one for the establishment of a lymphoid line and the other for short-term culture, which was used to estimate bleomycin sensitivity by cytogenetic procedures. Twenty lymphoid lines were selected at random to compare bleomycin sensitivity with data obtained from short-term lymphocyte cultures. In each set, bleomycin sensitivity of lymphoid cells was similar to that of the lymphocytes. The lymphoid lines, which can be propagated for an unlimited supply of relatively homogeneous cellular material, will be useful for a variety of future investigations. This investigation was supported by grants from the John S. Dunn Foundation, Houston, TX, the Esther Knispel Fund administered by The University of Texas M. D. Anderson Cancer Center, Houston, TX, and Department of Health and Human Services PHS grant DE 07007.     

人体基因组随机单拷贝顺序的分离及其在染色体上的定位

本文从构建杂种细胞14-7-1的基因组文库出发,用种特异的探针分离出含有人体基因组顺序的重组子,并进一步分析了其中13个克隆,得到8个单拷贝顺序。通过与已建立的杂种细胞克隆分布板杂交以及染色体的原位杂交方法,将1个单拷贝顺序FD11-1定位在11p11-q11上。由于已经报道在11号染色体上具有3个连锁群,它们分别位于11p15、11p13和11q13上,因此,FD11-1有可能为11号染色体连锁基因图的建立提供1个有意义的座位。     

Phosphorylation and nuclear localization of the varicella-zoster virus gene 63 protein.

The protein encoded by varicella-zoster virus open reading frame 63 and carboxy-terminal deletions of the same were expressed either as fusion proteins at the carboxy terminus of the maltose-binding protein in Escherichia coli or independently in transfected mammalian cells. The truncations contained amino acids 1 to 142 (63 delta N) or 1 to 210 (63 delta K) of the complete 278-amino-acid primary sequence. Recombinant casein kinase II phosphorylated the 63F and 63 delta KF fusion proteins in vitro but did not phosphorylate the 63 delta NF fusion protein, implying that phosphorylation occurred between amino acids 142 and 210. Immunoprecipitation of 35S- or 32P-labelled extracts of cells transfected with plasmids expressing 63, 63 delta N, or 63 delta K also indicated that in situ phosphorylation most likely occurred between amino acids 142 and 210. These combined results suggest that casein kinase II plays a significant role in the phosphorylation of the varicella-zoster virus 63 protein. Indirect immunofluorescence of transfected cells indicated nuclear localization of the 63 protein and cytoplasmic localization of 63 delta K and 63 delta N, implying a requirement for sequences between amino acids 210 and 278 for efficient nuclear localization.     

几种昆虫生长调节剂对家白蚁的毒效试验

在室内条件下测定了卡死克、抑太保、灭幼豚3号、爱力螨克和扑虱灵五种昆虫生长调节剂对家白蚁的毒杀效果。初步筛选结果表明：卡死克、抑太保和爱力螨克对家白蚁的毒杀效果均较好,家白蚁对爱力螨克尤其敏感。2．30pm。yL爱力螨克、327．36pm0VL、卡死克和369．80V＊wL抑太保处理白蚁5～6天后,其死亡率可达100％。忌避性试验表明：卡死克、抑太保和爱力螨克对家白蚁均无明显的驱避作用。