The protein,lipid and carbohydrate composition of protein bodies from Lupinus angustifolius seeds

Protein bodies isolated from dehulled seeds of Lupinus angustifolius (cv New Zealand Bitter Blue) contained 73 % protein, of which 78 % were globul     

Isolation and Amino Acid Composition of Ribosomal Proteins from Bacillus stearothermophilus

Twelve of the proteins from the 30S ribosome of Bacillus stearothermophilus were isolated by preparative disc electrophoresis. Amino acid analyses of these proteins showed them to be different from each other. The gross amino acid composition of 30S ribosomal protein from B. stearothermophilus and Escherichia coli are virtually identical. A number of the proteins of B. stearothermophilus had electrophoretic mobilities similar or identical to 30S ribosomal proteins of E. coli. However, there was little similarity between the two organisms in amino acid composition of individual proteins. There were no unusual chemical features of the B. stearothermophilus proteins which could explain the relative thermal stability of this organism's ribosomes.     

The Partial Characterization of the Major Seed Storage Proteins in Arabidopsis thaliana L.

This study was aimed at the characterization of the major storage proteins in Arabidopsis thaliana. Two major protein fractions, i.e., the fraction Ⅰ and Ⅱ proteins, were isolated from the extract of mature seeds of this plant by molecular seive gel filtration chromatography. Various polyacrylarnide gel electrophoretic techniques were used to study the properties and polypeptide compositions of these two protein fractions. In was shown that during the SDS gel electrophoresis, fraction Ⅰ protein was separated into 6 major bands with the mol. was. of 34, 31, 29, 28 and 19-20 kD, respectively, whereas Fraction Ⅱ protein migrated as 3 low mol. wt. bands (10-12 kD) on the same gel. Non-denaturing native gel electrophoresis revealed that fraction Ⅰ was a neutral protein and Fraction Ⅱ was a positively charged basic protein with an isoelectric point (pI) higher than 8.8. Fraction I protein was further separated into at least 16 polypeptides in isoelectric focusing/SDS two-dimensional gel electrophoresis, i.e. each SDS band contained 3-4 polypeptides with the same mol. wt. but different pis. This suggested a more complex polypeptide composition of this protein. The properties of fraction Ⅰ and Ⅱ proteins were in good accordance with that of the 12s and 1.7s storage globulins in seeds of many other dicotyledonous plants, and therefore had been characterized as the two major seed storage proteins in this species. These two storage globulins were shown to be accumulated within a defined period during the late stage of seed development (12-14 DAF) and became predominant protein components in mature seeds. In the mean time, a few points in relation to the polypeptide composition and subunit molecular configuration of the 12s globulin were noted.     

α-D-mannosidase and α-D-galactosidase from protein bodies of Lupinus angustifolius cotyledons

Two forms of p-nitrophenyl α-D-mannosidase and p-nitrophenyl α-D-galactosidase were purified from the protein bodies of mature Lupinus angustifolius seeds. A MW of 300 000 was calculated for both α-mannosidase A and B with K_m = 1.92 and 2.70 mM and activation energies of 10.9 and 10.8 kcal/mol, respectively. α-Galactosidase I and II had MWs of 70800 and 17000 with K_m = 0.282 and 0.556 mM and activation energies 17.7 and 11.5 kcal/mol, respectively. The enzymes had acid pH optima and were inhibited by various metal ions, carbohydrates and glycoproteins. They were able to release free sugar from several putative natural substrate oligosaccharides and the Lupinus storage glycoprotein, α-conglutin.     

Studies on Nuclei of Paramecium aurelia. II. Amino Acid Composition and Electrophoretic Properties of the Chromosomal Basic Proteins*

SYNOPSIS. The basic proteins of Paramecium aurelia nucleus were extracted from isolated nuclei and deoxyribonucleoprotein (DNP) of such nuclei. About 35–40% of the nuclear protein, predominantly a lysine-rich histone, is acid soluble. Five major components of the histone can be distinguished by polyacrylamide gel electrophoresis. Some components of Paramecium histone are similar to those of mammalian histones in their electrophoretic mobility, but they differ from the latter in the electrophoretic velocity and relative levels. The basic to acidic amino acid ratio of the histone from the ciliate is ～1.1–1.5, and its amino acid composition resembles closely that of yeast histone. Through the use of Sephadex G-200 gel filtration for purification of the histones extracted directly from isolated nuclei 2 basic proteins were resolved—component I, with an elution volume of 1.4, constitutes ～20% and component II, with an elution volume of 1.9, ～80%.     

基于氨基酸组成分布的嗜热和嗜冷蛋白随机森林分类模型

文献报道采用氨基酸组成分布提取特征值能有效提高预测分类精度, 本文采用该方法提取特征值, 使用一种新的组合分类器——随机森林, 从蛋白质一级结构对嗜热和嗜冷蛋白进行分类。通过10倍交叉验证和独立样本测试两种方法检测, 结果表明：当分段数量为1时, 其精度最优, 分别为92.9％和90.2％, 暗示使用基于氨基酸组成分布提取特征值在该算法中并不能有效提高识别精度, 这与报道结果不符, 而该提取方法在SVM中却能适当提高识别精度; 当引入6个新变量后, 其精度分别提高到93.2%和92.2%, ROC曲线下面积分别为0.9771和0.9696, 优于其它组合分类器。     

基于氨基酸组成分布的嗜热和嗜冷蛋白随机森林分类模型

文献报道采用氨基酸组成分布提取特征值能有效提高预测分类精度, 本文采用该方法提取特征值, 使用一种新的组合分类器——随机森林, 从蛋白质一级结构对嗜热和嗜冷蛋白进行分类。通过10倍交叉验证和独立样本测试两种方法检测, 结果表明：当分段数量为1时, 其精度最优, 分别为92.9％和90.2％, 暗示使用基于氨基酸组成分布提取特征值在该算法中并不能有效提高识别精度, 这与报道结果不符, 而该提取方法在SVM中却能适当提高识别精度; 当引入6个新变量后, 其精度分别提高到93.2%和92.2%, ROC曲线下面积分别为0.9771和0.9696, 优于其它组合分类器。     

The Molecular Biology of Euglena gracilis. X. Amino Acid Composition of Protein

SYNOPSIS. Cells of Euglena gracilis strain Z were extracted with trichloroacetic acid. Samples of gross cellular protein were hydrolyzed by a variety of reagents. Amino acids released by these procedures were analyzed and the overall composition of cell protein was quantitatively determined.     

Changes in Composition of Soluble Intercellular Proteins Isolated from Healthy and TMV-Infected Nicotiana tabacum L. cv. Xanthi-nc

Changes in ribonucleases (RNases), phosphomonoesterase (PME), phosphodiesterase (PDE), glucose-6-phosphate dehydrogenase (G6P DH), polyphenoloxidases, peroxidases and proteases activity and PR-proteins composition in leaf tissue and intercellular fluid (ICF) isolated from leaf tissue of healthy and TMV-infected hypersensitive tobacco (Nicotiana tabacum L. cv. Xanthi-nc) plants (non-inoculated leaves) were studied. The amount of the proteins and the enzymes of intercellular space was less than 3 % of the total amount of proteins and the enzymes found in homogenate of healthy leaves. The TMV infection did not significantly change this observation. The great increase in the activities of the enzymes was observed in homogenates of the infected leaves, especially of the enzymes involved in biosynthesis of precursors needed for virus multiplication (G6P DH, RNase, PME, PDE). This is in contrast with the activities of the enzymes of ICF, which were only partly increased. The ICF proteins of infected plants were separated by means of ion exchange chromatography on DEAE cellulose. The isozymes of peroxidase, polyphenoloxidase, PME and PDE were identified. Using discontinuous nondenaturating polyacrylamide gel electrophoresis of DEAE cellulose fractions, the detection of isozymes of peroxidases and PR-proteins was performed. By means of SDS-PAGE the molecular masses of PR-proteins were identified: 15 – 16 kDa (group 1), 27 – 28 kDa (group 3: chitinases) and 36 – 40 kDa (group 2a: -1,3-glucanases).     

Isolation and Characterization of Two Fatty Acid Binding Proteins from Mouse Brain

Abstract: Two fatty acid binding proteins (FABPs) were isolated from Swiss Webster mouse brains. Neither protein cross-reacted with antisera to recombinant liver L-FABP. One protein, designated brain H-FABP, migrated on tricine sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) as a single band at 14.5 kDa with pl 4.9. Brain H-FABP bound NBD-stearic acid and cis -parinaric acid with K _D values near 0.02 and 0.5 µ M , respectively. Brain H-FABP cross-reacted with affinity-purified antisera to recombinant heart H-FABP. The second protein, mouse brain B-FABP, migrated on tricine SDS-PAGE gels as a doublet at 16.0 and 15.5 kDa with pl values of 4.5 and 4.7, respectively. Brain B-FABP bound NBD-stearic acid and cis -parinaric acid with K _D values near 0.01 and 0.7 µ M , respectively. The brain B-FABP doublet was immunoreactive with affinity-purified antibodies against recombinant mouse brain B-FABP, but not with affinity-purified antibodies against heart H-FABP. [³H]Oleate competition binding indicated that the two brain FABPs had distinct ligand binding specificities. Both bound fatty acids, fatty acyl CoA, and lysophosphatidic acid. Although both preferentially bound unsaturated fatty acids, twofold differences in specific saturated fatty acid binding were observed. Brain B-FABP and brain H-FABP represented 0.1 and 0.01% of brain total cytosolic protein, respectively. In summary, mouse brain contains two native fatty acid binding proteins, brain H-FABP and brain B-FABP.     

Isolation and Identification of Specific Cortical Proteins in Tetrahymena pyriformis strain GL*†

SYNOPSIS. Pellicles of the ciliate Tetrahymena pyriformis strain GL (phenoset A) were isolated by a new procedure. Oral apparatuses were also purified by a modification of a previous method. Both preparations were characterized by electron microscopy. Proteins of the isolates were separated by analytical SDS polyacrylamide gel electrophoresis. The isolated pellicles, which included oral apparatuses, contained only 6 major proteins (gel bands), designated A through F. Bands A, B, and C, were found in the pellicle fraction, but not in the oral apparatus fraction. Therefore, these proteins are believed to be present in the somatic cortex of Tetrahymena. Bands D and E were greatly enriched in the oral apparatus fraction; these proteins are therefore believed to be present primarily in the oral apparatus. Band F, identified as tubulin, was present in both preparations. Molecular weight determinations and some selective solubilization experiments are also presented.     

盐度对哈氏仿对虾肌肉一般营养成分和氨基酸组成及含量的影响

通过调查不同盐度(12～36)环境下养殖的哈氏仿对虾(Parapenaeopsis hardwickii)肌肉一般营养成分和氨基酸组成及含量,研究了盐度对该虾肌肉营养品质的影响。结果显示,肌肉的水分随环境盐度升高出现显著的直线下降,而粗蛋白含量随环境盐度升高而直线升高;各盐度组的粗脂肪含量虽然没有明显差异,但其含量随盐度升高有一定的线性下降趋势;36盐度组的粗灰分含量比12、16、20和28盐度组的明显高,32盐度组的灰分含量比20和24盐度组的也明显高;所检测的肌肉干样16种氨基酸中,只有3种氨基酸的含量随盐度升高而升高,而其他13种氨基酸的含量随盐度升高明显降低,其中有10种氨基酸的含量在盐度12～24条件下的比盐度28～36条件下的明显高,而这些氨基酸含量在盐度12～24之间没有明显差异。各盐度组间氨基酸总量和鲜味氨基酸含量均没有明显差异;必需氨基酸和半必需氨基酸含量在盐度12～24条件下的均比盐度28～36条件下的明显高,而在12～24盐度组之间以及28～36盐度组之间均没有明显差异。必需氨基酸/氨基酸总量的比值和必需氨基酸/非必需氨基酸比值随盐度升高均明显线性降低;盐度12～24组的必需氨基酸指数(66.13～67.42)高于盐度28～36组的(62.56～64.46)。综上所述,盐度12～24环境下养殖的哈氏仿对虾肌肉营养价值相对较高,表现为低盐趋向,考虑到肌肉的水分含量和生长性能,哈氏仿对虾在养殖期间选择16～24盐度范围比较合适,同时也说明哈氏仿对虾适合大多数沿海地区环境的盐度条件。     

Isolation of legumin-like protein from Phaseolus aureus and Phaseolus vulgaris

An 11S seed globulin has been isolated from Phaseolus aureus and P. vulgaris by zonal isoelectric precipitation and the MWs of the constituent subunits determined. The protein of P. vulgaris occurs in the protein body fraction and its chemical composition, including the N-terminal amino acids and amino acid composition has been determined. The similarity between the 11S globulin of the two Phaseolus spp. and legumin from other leguines is discussed.     

Isolation and Characterization of Antidermatophytic Bioactive Molecules from Piper longum L. Leaves

Piper longum L. (Piperaceae) commonly known as “long pepper” is a well known medicinal plant in ayurveda. Different parts of this plant, such as root, seed, fruit, whole plant etc. are used traditionally in various ailments. Here we have investigated the antidermatophytic activity of sequentially extracted petroleum ether, chloroform, methanol and water extracts from P. longum leaf against Trichophytonmentagrophytes, T. rubrum, T. tonsurans, Microsporum fulvum and M. gypseum. Better activity of chloroform and methanol extracts was observed. The chloroform extract was selected for further study and the MIC value was recorded as 5.0 mg ml⁻¹ against the test organisms. In the chloroform extract, tannins and phenolic compounds were detected. Further activity-guided fractionation of chloroform extract by silica gel column chromatography yielded nine major fractions. Among these, fraction-1, 4, 5 and 7 showed higher antidermatophytic activity. Fraction-4 on further purification by repeated column chromatography yielded a potential antidermatophytic fraction showing MIC value of 0.625 mg ml⁻¹ against T. mentagrophytes and T. rubrum as determined by broth microdilution method. The major compounds were identified as 1,2-benzenedicarboxylic acid, bis(2-ethylhexyl) ester (C₂₄H₃₈O₄] (41.45 %), 2,2-dimethoxybutane (C₆H₁₄O₂] (13.6 %) and β-myrcene (C₁₀H₁₆) (6.75 %) based on GC–MS data.     

The Isolation and Structural Determination of r-harmine from the Seed of Peganum harmala L.

γ-Harmine, a new carboline alkaloid isolated from Peganum harmala L. (Zygophylaceae), has been shown to be 7-methoxy-4-methyl-γ-carboline (Ⅵ) according to its color reaction and spectral analyses. This is the first γ-carboline compound isolated from a plant, Harmine (Ⅰ) has also been isolated from the same plant material.     

家蚕雌性附腺及其Ng突变体蛋白质组双向电泳图谱分析

分别对家蚕(Bombyx mori．L)正常及Ng突变体雌蛾件附腺分泌部组织的蛋白质进行提取,并采用双向凝胶电泳和计算机辅助分析方法,对提取的蛋白质混合物进行分离和比较分析。用银染的方法,平均每张电泳图谱可以分离约700个蛋白质点,其中大部分的蛋白质点分布在pH4～8范围内,在分子量上主要集中在30～70kD区域：比较分析发现,有4种蛋白只在正常性附腺组织中特异表达,而有2种蛋白只在Ng突变体的组织中特异表达。另外约有29种蛋白在正常性附腺分泌部组织中的表达水平明显高于Ng突变,而约有15种蛋白在Ng突变体的分泌部组织中表达水平较高。这些差异蛋白质可能与Ng突变的形成和导致这种突变体的性附腺不能正常分泌粘性蛋白的性状有关。     

芸苔（菜心）茎叶中的几丁质结合蛋白的分离纯化和某些特性分析

用脱氨再生几丁质亲和层析和羧甲基-纤维素CM52离子交换柱层析从芸苔（菜心）的茎叶中纯化了4种几丁质结合蛋白：CBPa,CBPb、CBPc和CBPd,SDS-PAGE显示CBPa和CBPb的分子量分别为29．04kDa和30．68kDa。凝胶过滤方法测定CBPa和CBPb的分子量分别为29．04kDa和31．2kDa,表明两者都是单体酶。4种CBP蛋白均有几丁质酶活性,其中CBPa和CBPb还有溶菌酶活性。EDTA对CBPa和CBPb溶菌酶的活性均无影响,各种类型的几丁质对CBPa和CBPb都有较强的吸附作用,PAS染色法分析表明CBPa和CBPb均为糖蛋白。