家蚕抗菌蛋白Cecropin D和Lysozyme的分离纯化及性质鉴定

经大肠杆菌E．coli K12D31诱导后的家蚕幼虫，其免疫血淋巴经CM-Sepharose CL-6B离子交换层析、Sephadex G-100凝胶过滤层析及HPLC分离后，得到2种抗菌蛋白，经液相色谱-电喷雾质谱（ESI-MS）分析鉴定，纯化的2种抗菌蛋白分别是家蚕抗菌肽eeeropin D和溶菌酶lysozyme酸性电泳（A-PAGE）测活免疫血淋巴得到抗菌蛋白活性谱：cecropin D在8h无显著表达，12h有较强抗菌活性，30h达到最高，以后逐渐降低；lysozyme在8h后检测到表达，12h到达高峰，之后逐渐下降，48h的血淋巴中未检测到明显的表达．研究认为抗菌蛋白lysozyme和cecropin D是家蚕幼虫感染细菌8h后大量表达的抗菌蛋白，主要参与细菌感染12～30h的血淋巴对细菌的清除，是参与家蚕幼虫抗菌免疫的重要蛋白．     

人工饲料育家蚕/杆状病毒表达猪瘟病毒囊膜糖蛋白E2基因

以重组病毒Bm-BacPAK6-E2接种全龄人工饲料育及5龄桑叶育家蚕皓月×菁松幼虫、蛹,观察重组病毒的感染发病情况,调查病蚕、蛹的采血量并进行SDS-PAGE分析.结果表明,全龄人工饲料育家蚕接种重组病毒的成功率、采血量等指标均与5龄桑叶育相近,SDS-PAGE蛋白质电泳在家蚕幼虫、蛹血淋巴中均检测到1条与目的蛋白理论分子量(63 kD)相符的特异性蛋白条带,初步认为是重组病毒Bm-BacPAK6-E2的融合表达产物.     

麻蚕各发育期血淋巴中游离氨基酸的测定

血淋巴中含有大量游离氨基酸,是昆虫生物化学主要特征之一。昆虫血中游离氨基酸的浓度比人血高20—100倍。近年来纸谱分析了许多昆虫血淋巴中的游离氨基酸,组成蛋白质的20种氨基酸都曾在昆虫血淋巴中找到了。在鳞翅目的幼虫及蛹中,曾观察到血淋巴中氨基酸在各发育阶段上的差异,这些差异可能与变态期间体内的代谢有关,近数年来     

KK-42对日本沼虾蜕皮激素及其受体表达的影响

用1.95×10-4 mol.L-1的KK-42处理日本沼虾1min,不同时刻抽取血淋巴、解剖肝胰腺.HPLC测定血淋巴中20E滴度,RT-PCR测定EcR和RXR mRNA水平.结果:KK-42处理后3h,6h,20E滴度分别比对照组增加了121.71%(P<0.05)、268.96%(P<0.01);EcR mRNA水平在处理后6h,12h,分别比对照组提高了233.56%(P<0.01)、110.73%(P<0.05);RXR mRNA水平在处理后3h、12h,分别比对照组提高了195.53%(P<0.01)、80.83%(P<0.05).表明KK-42可显著提高血淋巴中20E的滴度,并诱导肝胰腺中EcR和RXR的基因转录.     

粘虫(Mythimna separata)变态期间环核苷酸和蜕皮激素的动态及灭幼脲的影响

本文用放射免疫法研究了粘虫(Mythim(?) (?) parata(walker))末龄幼虫和蛹初期的脑和前胸腺cAMP含量及血淋巴20-羟基蜕皮酮滴度的动态变化,进而研究了灭幼脲对这两种物质的影响.结果表明:(1)粘虫末龄幼虫仅具一个血淋巴20-羟基蜕皮酮的释放高峰,化蛹后则以更快的增长速度提高滴度,至蛹3日龄仍无衰减之势;(2)末龄幼虫前胸腺cAMP高峰出现后12小时,血淋巴中出现20-羟基酮释放峰位.而蛹1日龄出现前胸腺cAMP高峰后的较长时间内仍有血淋巴20-羟基蜕皮酮的持续增加;(3)末龄幼虫脑cAMP峰较前胸腺的峰位提早24小时发生,1日龄蛹前胸腺发生cAMP高峰前,脑的cAMP量也维持在较高水平;(4)1日龄末龄幼虫经灭幼脲处理后,脑和前胸腺的cAMP峰值以及血淋巴20-羟基蜕皮酮峰值分别降低约47％(P<0.001),25％(P<0.025)和75％(P<0.001),峰值期以外的cAMP量和激素滴度均无显著影响.     

中国柞蚕血淋巴的盘状电泳

应用聚丙烯酰胺凝胶盘状电泳法对中国柞蚕血淋巴中的蛋白质进行分离。实验结果表明，昆虫血淋巴中的蛋白质种类远较高等生物和人的少，而且还发现不同品种间的柞蚕血淋巴中蛋白质种类和分子大小也不同，从而为蚕的分类学和饲节理论根据。     

柞蚕抗菌蛋白纯化及性质

从雄性柞蚕（Ａｎｔｈｅｒａｅａ ｐｅｒｎｙｉ）蛹中分离和纯化抗菌蛋白。该抗菌蛋白由大肠杆菌诱导产生,经过ＳｅｐｈａｄｅｘＧ－５０分离纯化,在ＳＤＳ－ＰＡＧＥ检测中表现为一条带,分子量在１５ｋＤａ左右。纯化产物对大肠杆菌有明显抗菌活性,对血细胞没有凝集作用,是抗菌蛋白。     

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.     

柞蚕抗菌蛋白纯化及性质

从雄性柞蚕（ Ａｎｔｈｅｒａｅａ ｐｅｒｎｙｉ） 蛹中分离和纯化抗菌蛋白．该抗菌蛋白由大肠杆菌诱导产生,经过 Ｓｅｐｈａｄｅｘ Ｇ５０ 分离纯化,在 Ｓ Ｄ Ｓ Ｐ Ａ Ｇ Ｅ 检测中表现为一条带,分子量在１５ ｋ Ｄａ 左右．纯化产物对大肠杆菌有明显抗菌活性,对血细胞没有凝集作用,是抗菌蛋白．     

一种家蝇幼虫热稳定抗菌肽的分离纯化

本文对家蝇三龄幼虫进行了超声处理，以诱导其产生抗菌物质。通过高温处理、酸性处理后，抗菌物质粗提中大量的热不稳定蛋白和酸性蛋白发生沉淀而被去除。将经过上述处理的粗提液经过一步Sephadex G-75凝胶过滤析、两步CM－Sepharose阳离子交换层析后，得到一个单一的具有抗阳性球菌的峰。SDS－聚丙烯酰胺凝胶电泳结果显示为一条带，相对分子质量大约为7000，将其命名为H1．H1为一种热稳定的碱性抗菌多肽。     

家蚕,蓖麻蚕,樗蚕,樟蚕核型研究

探讨了蚕类染色体制片方法和分带技术，分析了家蚕，蓖麻蚕，樗蚕和樟蚕的核型，并对染色体的识别问题进行了讨论。     

蓖麻蚕触角的结构和嗅觉感受细胞对化学气味物质的反应

扫描电镜和透射电镜观察蓖麻蚕的触角和毛形感器。雄蛾触角上的毛形感器比雌蛾的长且多。雄蛾触角的每个毛形感器内有二个或三个树突。用４１种人工合成化合物刺激蓖麻蚕触角，单细胞记录方法记录感受细胞的感受器电位和神经冲动发放发现，雄蛾对Ｅ６，Ｚ１１－十六碳二烯醛和Ｅ４，Ｚ９－十四碳二烯醇，酯及醛反应明显。雌蛾触角对上述化合物无反应。     

非损伤性取样的蚕类DNA提取及检测

对家蚕和蓖麻蚕的蚕蜕和蛾翅分别采用SDS裂解法和动物组织基因组试剂盒提取法提取DNS，并与常规方法以蚕蛹提取的DNA一起进行RAPD扩增图谱比较、分析，结果表明用非损伤性方法提取的DNA的RAPD图谱和常规方法提取的DNA的RAPD图谱基本一致。     

Solid-state NMR determination of the secondary structure of Samia cynthia ricini silk

Silks are fibrous proteins that form heterogeneous, semi-crystalline solids. Silk proteins have a variety of physical properties reflecting their range of functions. Spider dragline silk, for example, has high tensile strength and elasticity, whereas other silks are better suited to making housing, egg sacs or the capture spiral of spiders' webs. The differing physical properties arise from variation in the protein's primary and secondary structure, and their packing in the solid phase. The high mechanical performance of spider dragline silk, for example, is probably due to a beta-sheet conformation of poly-alanine domains, embedded as small crystallites within the fibre. Only limited structural information can be obtained from diffraction of silks, so further characterization requires spectroscopic studies such as NMR. However, the classical approach to NMR structure determination fails because the high molecular weight, repetitive primary structure and structural heterogeneity of solid silk means that signals from individual amino-acid residues cannot be resolved. Here we adapt a recently developed solid-state NMR technique to determine torsion angle pairs (phi, psi) in the protein backbone, and we study the distribution of conformations in silk from the Eri silkworm, Samia cynthia ricini. Although the most probable conformation in native fibres is an anti-parallel beta-sheet, film produced from liquid directly extracted from the silk glands appears to be primarily alpha-helical.     

蓖麻蚕性细胞发育过程染色体的银染观察

用银染法观察了蓖麻蚕生殖细胞的染色体。结果表明：有丝分裂中期染色体上无特异的ＮＯＲｓ；精母细胞减数分裂偶线期和粗线期核仁逐步弥散，粗线期之后有一个染色体分散为染色质，核仁弥散于其中形成嗜银的二价体的第二收缩期和混乱期；卵母细胞的相应时期，有一个核仁扩增的过程。依据染色体嗜银性的强弱，探讨了前期Ⅰ，中期Ⅰ以及有丝分裂中期染色体的ｒＤＮＡ转录活性。     

Antisera to a synthetic peptide of the sis viral oncogene product recognize human platelet-derived growth factor

It has recently been reported that the sequences of the sis oncogene of simian sarcoma virus (SSV) and of human platelet-derived growth factor (PDGF) are very similar, establishing the most solid link yet between the mitogenic actions of growth factors and the transforming proteins of retroviruses. To investigate molecular mechanisms of transformation I have produced antisera against synthetic peptides corresponding to segments of the protein sequences predicted by the nucleotide sequences of viral oncogenes. Applying this approach to the case of sis and PDGF, I report here the results of probing outdated human platelets with an antiserum directed against a synthetic peptide representing residues 139-155 of the predicted sequence of the SSV transforming protein, p28sis (ref. 3). I detected peptides of apparent molecular weights (MWs) 30,000 to 31,000 (30-31K) and 16-18K, which correspond to the apparent molecular weights of nonreduced and reduced PDGF. In addition, a peptide of MW 21,000 was detected in platelets and a protein of MW 56,000 was detected in SSV-infected marmoset cells.     

Subunit of the '20S' proteasome (multicatalytic proteinase) encoded by the major histocompatibility complex

Cytotoxic T lymphocytes recognize fragments (peptides) of protein antigens presented by major histocompatibility complex (MHC) class I molecules. In general, the peptides are derived from cytosolic proteins and are then transported to the endoplasmic reticulum where they assemble with the MHC class I heavy chains and beta 2-microglobulin to form stable and functional class I molecules. The proteases involved in the generation of these peptides are unknown. One candidate is the proteasome, a nonlysosomal proteinase complex abundantly present in the cytosol. Proteasomes have several proteolytically active sites and are complexes of high relative molecular mass (Mr about 600K), consisting of about 20-30 subunits with Mrs between 15 and 30K. Here we show that at least one of these subunits is encoded by the mouse MHC in the region between the K locus and the MHC class II region, and inducible by interferon-gamma. This raises the intriguing possibility that the MHC encodes not only the MHC class I molecules themselves but also proteases involved in the formation of MHC-binding peptides.     

陆地棉花粉成熟过程中特异性蛋自及单花粉电泳研究

本文对不同发育时期的花粉剥出后进行蛋白电泳，结果表明，不同发育时期的花粉其蛋白、过氧化物同工酶和酯酸都有差异，花粉在成熟过程中，伴随着过氧化物酶活性的消失和种类的减少；在花粉进行第一次细胞分裂形成营养细胞和生殖细胞之前，新的蛋白带和酯酶带的出现，尤其是近十种蛋白的大量合成提示这些蛋白在花粉成熟和以后的受精过程中可能有重要作用。对其成熟的花粉进行单花粉电泳表明，没有等位基因的分离现象，只是有约２％的花粉出现新的蛋白带，其原因有待进一步研究。     

Sequence analysis of peptides with biological activities using electrospray-Fourier trans form ion cyclotron resonance mass spectrometry

The mass spectra of five peptides with biological activities are reported. All mass spectra were recorded using a 4.7-T Fourier transform ion cyclotron resonance mass spectrometer equipped with an external electrospray source. The accurate molecular weights for the five peptides prepared by solid phase synthesis were measured as 1765.9013, 1063.5420, 1092.5254, 820.3804 and 1078.5193, respectively. All the data were obtained with the external calibration. Differences between observed and theoretical monoisotopic molecular weights were in the (0.2—1.0)×10^-6 range. The complete primary sequence for the five polypeptides were determined using the method of in-source electrospray ionization/collision induced dissociation (ESI/CID). All the intact y series ions and b series ions were obtained from various peptides respectively, thus determining the sequences of the five polypeptides. We found that the measured accurate molecular mass of sample 4 was not in agreement with that expected from the planned synthetic peptide. The sequences of sample 4 were determined through analysis. The corresponding accurate masses of b series ions and y series ions were gained, which proved that it was correct to re-determine the sequences.