Hydroxylated glutamic acids in Phlox,lepidium and Rheum species

The two diastereoisomers, (2S,4R)-4-hydroxyglutamic acid and (2S,4S)-4-hydroxyglutamic acid, occur in characteristic concentration ratios in Phlox species. The second of these compounds is the principal free amino acid in the green parts of the plants. The presence of (2S,4R)-4-hydroxyglutamic acid in plants is reported for the first tiine. No other 4-substituted acidic amino acids were detected in the Phlox species analysed, although special attention was paid to the possible presence of 4-hydroxy-4-methylglutamic acids which have previously been reported in plants. It was found, however, that both diastereoisomers of (2S)-4-hydroxy-4-methylglutamic acid co-exist in Ledenbergia roseoaenea and also in Pandanus veitchii. Although the presence of 3,4-dihydroxyglutamic acids in green parts of Lepidium sativum and Rheum rhaponticum has been previously reported, we were not able to detect or isolate any of the possible diastereoisomers from the green parts or seeds of these plants. We did isolate glutathione which was found to have some properties in common with those reported for the dihydroxy compounds.     

The constancy and similarity of the amounts of free amino acids in inbred strains of Drosophila and outbred Calliphora

The composition of the free amino acids are compared in adults of two inbred strains of Drosophila subobscura and their hybrids, three inbred lines of Drosophila melanogaster, and in flies from a heterogeneous population of Calliphora erythrocephala. It appears that not only do the amounts of amino acid vary very little from fly to fly, but also very little between inbred lines. Furthermore, the relative amounts of the amino acids in Drosophila are similar to the relative amounts in the blowfly, Calliphora. This characteristic of invariant amounts of the free amino acids in these Diptera occurs in spite of the probably large numbers of genes affecting them.     

Small peptides,a life-long store of amino acid in adult Drosophila and Calliphora

A sizable component of small peptide is probably an important store of amino acid in Calliphora and Drosophila. Quantitative amino acid analysis of the peptides in adult male Calliphora erythrocephala and Drosophila subobscura show that their composition is very similar. It is shown in Calliphora that the amount of peptide present in adults varies with age and feeding regime. Further, the peptide composition of the haemolymph indicates that the peptides are stored intracellularly. However, there is evidence which suggests that their hydrolysis takes place in the haemolymph, thus providing the whole fly with free amino acid and the haemolymph with osmotic stability.     

Proteinase inhibitors from Erythrina corallodendron and Erythrina cristagalli seeds

Eight and five proteinase inhibitors were purified from Erythrina corallodendron and E. cristagalli seeds, respectively, by gel filtration followed by ion exchange chromatography on DEAE-cellulose and DEAE-sepharose. Each inhibitor consists of 161–163 amino acids (M_r 18 000) including four half-cystine residues and resembles the Kunitz-type proteinase inhibitors. The N-terminal amino acid sequence of trypsin inhibitor DE-7 from E. corallodendron seed resembles those of other Erythrina species. For the other inhibitors no free N-terminal amino acid was found. DE-1,-2,-3,-4 and -5 from the seed of E. corallodendron contain potent inhibitors for α-chymotrypsin and they have practically no action on trypsin. From the same seed, inhibitors DE-6, -7 and -8 strongly inhibit trypsin and also inhibit α-chymotrypsin to varying degrees. From the seeds of E. cristagalli, inhibitors DE-1 and -8 inhibit trypsin strongly and DE-2, -3 and -4 are strongly inhibitory for α-chymotrypsin. On summarizing the inhibitor characteristics of the Kunitz-type proteinase inhibitors from the seeds of eight different species of Erythrina, it was obvious that there is a relationship between the alanine content of the inhibitors and their activities. A high alanine content is associated with potent α-chymotrypsin activities and low alanine content with strong trypsin activities.     

Haemolymph amino acids and related compounds during cocoon production by the larvae of the fly, Rhynchosciara americana

A qualitative and quantitative analysis of free amino acids and related compounds in the haemolymph of Rhynchosciara americana was carried out for different periods of the fourth larval instar. Threonine, serine, proline, and glutamic acid make up 50 per cent of the total free amino acids in R. americana haemolymph just before the larvae start spinning the communal cocoon; after this the titre of most of the amino acids declines continuously. There are few peptides but these are present in high titres; they consist of two to three amino acid residues, of which the most important are histidine and aspartic acid. The fall in the haemolymph amino acid and peptide titres is insufficient to account for the silk protein which accumulates on the communal cocoon during the same period. The results are consistent with a silk protein origin from haemolymph proteins and haemolymph free amino acids. The origin and metabolic rôle of some haemolymph ninhydrin-positive compounds are discussed.     

Free amino acids in Crotalaria seeds

The free amino acids of seeds of 163 species of Crotalaria have been identified. Their pattern of distribution is compared with recent classifications of the genus and the possible ecological significance of their presence is discussed. Attention is drawn to the occurrence of toxic amino acids.     

Effect of sound and Lenzites-decayed wood on the amino acid composition of Reticulitermes flavipes

In hydrolysates of the eastern subterranean termite, Reticulitermes flavipes, the most abundant protein amino acids (μmoles) were glycine, alanine, and glutamic acid; the least abundant were methionine and histidine. Sawdust from both sound and Lenzites trabea-decayed sapwood blocks of sugar maple, loblolly pine, and slash pine was force-fed to termites. A diet of decayed rather than sound wood had little effect on protein amino acid composition of the termites; glycine content varied the most. In contrast, diet affected the free amino acid composition. Except for glutamic acid, the major protein amino acids of the termites were not the predominant free amino acids. Tyrosine and histidine were relatively more abundant as free than as protein amino acids. Greatest differences in protein amino acid compositions of sound and decayed wood were in contents of glycine, leucine, lysine, and arginine.     

ChAy/Bx, a novel chimeric high-molecular-weight glutenin subunit gene apparently created by homoeologous recombination in Triticum turgidum ssp. dicoccoides

High-molecular-weight glutenin subunits (HMW-GSs) are of considerable interest, because they play a crucial role in determining dough viscoelastic properties and end-use quality of wheat flour. In this paper, ChAy/Bx, a novel chimeric HMW-GS gene from Triticum turgidum ssp. dicoccoides (AABB, 2n = 4x = 28) accession D129, was isolated and characterized. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis revealed that the electrophoretic mobility of the glutenin subunit encoded by ChAy/Bx was slightly faster than that of 1Dy12. The complete ORF of ChAy/Bx contained 1671 bp encoding a deduced polypeptide of 555 amino acid residues (or 534 amino acid residues for the mature protein), making it the smallest HMW-GS gene known from Triticum species. Sequence analysis showed that ChAy/Bx was neither a conventional x-type nor a conventional y-type subunit gene, but a novel chimeric gene. Its first 1305 nt sequence was highly homologous with the corresponding sequence of 1Ay type genes, while its final 366 nt sequence was highly homologous with the corresponding sequence of 1Bx type genes. The mature ChAy/Bx protein consisted of the N-terminus of 1Ay type subunit (the first 414 amino acid residues) and the C-terminus of 1Bx type subunit (the final 120 amino acid residues). Secondary structure prediction showed that ChAy/Bx contained some domains of 1Ay subunit and some domains of 1Bx subunit. The special structure of this HMW glutenin chimera ChAy/Bx subunit might have unique effects on the end-use quality of wheat flour. Here we propose that homoeologous recombination might be a novel pathway for allelic variation or molecular evolution of HMW-GSs.     

Uric acid in nucleic and amino acid synthesis in the boll weevil, Anthonomus grandis

When uric acid-2-¹⁴C was injected into the boll weevil, Anthonomus grandis, it was metabolized to RNA, DNA, amino acid, and ¹⁴CO₂ at the end of 2 hr. The free amino acids, lipoamino acids, and protein amino acids were all labelled with the free amino acids showing the highest specific activity. Incorporation in DNA was slight, but it was extensive in RNA; cytidylic acid showed the greatest amount of incorporation.     

Amino acid and protein changes in the haemolymph of developing fourth instar Chironomus tentans

The concentration of free amino acids, total soluble protein, and haemoglobin in the haemolymph of fourth instar Chironomus tentans was investigated.The concentration of the free amino acid pool increases between the early (15.7 mM/l) and mid-(33.9 mM/l) fourth larval stages followed by a decline during the late (16.9 mM/l) fourth larval period. Alanine, serine, and the amides of aspartic acid and glutamic acid are the predominant free amino acids at all stages. Physiological fluid analysis of late fourth instar haemolymph detected 32 ninhydrin positive components including 18 common amino acids plus homoarginine, ornithine, citrulline, β-alanine, α-aminoadipic acid, α-aminoisobutyric acid, and sarcosine.The concentration of total soluble protein steadily increases during fourth instar larval development to a maximum of $\text{9.3}\text{g}\text{100}\text{ml}$ followed by a decline during the pharate pupal period. A similar pattern of variation occurs in haemoglobin content which comprises from 51 to 66% of Chironomus tentans haemolymph protein.The mM percentage of individual amino acids of total haemolymph protein varies little during the fourth instar. At all stages alanine and aspartic acid are the predominant amino acids.     

Free amino acids in Phycomyces blakesleeanus during development

In Phycomyces blakesleeanus the total level of free amino acids and their relative distributions change strikingly during the development of sporangiophores. Very high levels of serine, glutamate and histidine are found. The variety of amino acids becomes more restricted in sporangiophores grown on nitrogen-rich media; levels of arginine increase dramatically. The distribution differs in mycelia. No unusual amino acids or oligopeptides were found.     

Some features of the regulation of the free amino acids in adult Calliphora erythrocephala

The amounts of nearly every amino acid in Calliphora remain unchanged inspite of stress. Thus the free amino acid pool is regulated. The amounts of free amino acid in the haemolymph account for only a small part of the total free amino acid in a fly and therefore most free amino acid is located and regulated intracellularly. A comparison of the rates of conversion and turnover of glycine-C¹⁴ in flies fed protein and sugar and in flies fed sugar alone indicates that in the absence of a dietary source of amino acid, not only is the rate of total turnover appreciably lower but the rates of conversion to other amino acids also change. With a dietary source of amino acid, the rates of incorporation into protein account for only a part of the total turnover of each amino acid. With a sufficiency of amino acid, substantial amounts are probably used as an energy source.     

A novel ornithine-containing tripeptide isolated from the extract of the brackish-water bivalve Corbicula japonica

Previous studies have demonstrated that frozen preparations of the brackish-water bivalve Corbicula japonica significantly increase the content of free ornithine found in its extracts. Here we report a novel ornithine-containing tripeptide commonly found in C. japonica, which is believed to be the source of increased free ornithine. The new peptide, named acorbine, was isolated from extracts of this bivalve obtained using ultra-filtration and gel permeation chromatography. Acorbine is comprised of N²-[N²-(β-alanyl)-l-ornithyl]-l-ornithine as determined by amino acid composition analysis, N- and C-terminal amino acid analyses, proton nuclear magnetic resonance spectrometry, and chirality analysis of the ornithine residue. The total amount of β-alanine and ornithine in the extract remained constant regardless of the temperature at which the bivalve was processed. The amount of free β-alanine and ornithine increased significantly when the bivalve was frozen, with a corresponding decrease in peptidic β-alanine and ornithine. The results suggest that changing the growth conditions triggers tripeptide proteolysis within the bivalve, which ultimately manifests in increased free β-alanine and ornithine.     

Quantitative changes in free amino acids in Polytrichum formosum during development

The concentrations of each free amino acid in Polytrichum formosum have been determined for female gametangia at different developmental stages of     

三角鲂和长春鳊肌肉营养成分分析与品质评价

用常规方法测定、分析了三角鲂(Megalobrama tarminalis)和长春鳊(Parabramis pekinensis肌肉中营养成分组成与含量.结果显示,三角鲂肌肉蛋白质、脂肪含量分别为18.19％和3.06％,长春鳊肌肉蛋白质、脂肪含量分别为19.38％和2.89％.三角鲂和长春鳊肌肉中均检测出18种氨基酸,其中包括了8种人体必需氨基酸.三角鲂肌肉中氨基酸总量为76.27％,其中,8种人体必需氨基酸含量为32.17％,占氨基酸总量的42.18％;长春鳊肌肉中氨基酸总量为77.60％,其中,8种人体必需氨基酸含量为31.70％,占氨基酸总量的40.85％.必需氨基酸的构成比例基本符合FAO/WHO的标准.三角鲂肌肉中限制性氨基酸主要为甲硫氨酸加胱氨酸,必需氨基酸指数为63.55,4种呈味氨基酸为氨基酸总量的32.81％;长春鳊肌肉中限制性氨基酸主要为色氨酸,必需氨基酸指数为66.81,4种呈味氨基酸为氨基酸总量的33.80％.脂肪酸中二十碳五烯酸(EPA)与二十二碳六烯酸(DHA)含量均较高,三角鲂为7.96％,长春鳊为3.11％.矿物元素比值合理.以上分析表明,三角鲂和长春鳊均为营养价值、经济价值都较高的优质鱼类,相比而言,三角鲂肌肉脂肪、脂肪酸含量和质量更优,而长春鳊肌肉在蛋白质、氨基酸组成与含量方面更优.     

Cytochrome cs from Rhodymenia palmata and Porphyra umbilicalis and the amino acid sequences of their N-terminal regions

Basic c-type cytochromes homologous with plant and animal mitochondrial cytochrome c have been isolated and purified from Rhodymenia palmata and Porphyra umbilicalis. The N-terminal regions have been analysed using a Beckman 890C automatic sequencer. When compared to animal cytochrome c, the Rhodymenia cytochrome c has an unblocked N-terminal tail of 10 amino acids, whereas Porphyra has an unblocked N-terminal tail of only a single amino acid.     

Molecular characterization and expression analysis of Acmago and AcY14 in Antrodia cinnamomea

Mago nashi (Mago) and Y14 proteins, highly conserved among eukaryotes, participate in mRNA localization and splicing, and as such play important roles in oogenesis, embryogenesis and germ-line sex determination during animal development. Here we identified mago (Acmago) and Y14 (AcY14) homologues derived from Antrodia cinnamomea. Acmago encodes 149 amino acids and AcY14 encodes 168 amino acids. Multiple amino acid sequence alignment as well as secondary and tertiary structure prediction showed that AcMago and AcY14 have similar protein structure to the reported crystal structures of other Mago and Y14 proteins. During fungal development both Acmago and AcY14 genes were abundantly expressed in natural basidiomes. This is the first report of the molecular characterization and expression analysis of the mago and Y14 genes from fungi.     

Why the aphid Aphis spiraecola is more abundant on clementine tree than Aphis gossypii?

Aphis spiraecola and Aphis gossypii cause harmful damages on clementine tree orchards. Weekly surveys measured the abundance of aphids (larvae, winged and wingless adults) as well as of auxiliary insects and parameters of energy metabolism. Correlatively, soluble carbohydrates, total free amino acids, free proline and condensed tannins were quantified in control and infested leaves. Both aphid species showed parallel temporal variations, but A. spiraecola was consistently more abundant regardless of the stage. Amino acids had a positive effect on both aphid species abundance, but neither condensed tannins nor auxiliary insects seemed to modulate aphid populations. Interestingly, the leaf carbohydrate content was positively correlated with the abundance of A. spiraecola, but not with that of A. gossypii. Moreover, A. gossypii's abundance was significantly down-regulated by high proline concentrations. Thus, the higher abundance of A. spiraecola could be explained by a better tolerance to high proline contents and a better conversion of foliar energy metabolites.     

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.     

Mechanism of proline uptake by Chlorella vulgaris

An amino acid uptake system specific for glycine, alanine, serine and proline was induced by glucose in Chlorella vulgaris. The uptake system translocated the zwitterionic form of the amino acid. There was more than 100-fold accumulation which indicated a coupling to metabolic energy. The depolarization of the membrane potential during proline uptake and the sensitivity of its uptake rate to the membrane potential point to coupling with an ion flow. Inhibitors of plasmalemma-bound H⁺-ATPase inhibit proline uptake. These data are interpreted to mean that proline is taken up as a proton symport. In some Chlorella strains the proline-coupled H⁺ uptake could be measured with electrodes, but not in Chlorella vulgaris. There is evidence that the transport of amino acids rapidly stimulates the proton-translocating ATPase of Chlorella vulgaris, so that the proline-coupled proton uptake is immediately neutralized.