用高性能离子交换膜对猪毛水解废液的研究

猪毛酸解提取胱氨酸后的母液含有１７种氨基酸,采用我校由辐射法制得的高性能离子交换膜（ＨＦ－１及ＨＦ－２）,通过电渗析技术可对母液进行脱盐并制得混合氨基酸。本文就脱盐时氨基酸损失率、脱盐率作了讨论。     

氨基酸母液中含盐量的测定方法探讨

本文采用不同氯离子（Ｃｌ－）含量的测定方法（摩尔法、电位滴定法、氯离子选择性电极法）,探讨出适用于猪毛水解提取胱氨酸后的未脱盐氨基酸母液（简称母液Ⅰ）、脱盐氨基酸母液（简称母液Ⅱ）以及由母液Ⅱ经浓缩结晶出的固体氨基酸粉末中的Ｃｌ－含量测定的最佳方法。     

丝素蛋白粉制备工艺研究

用自制脱盐装置研究了高分子丝素蛋白的降解脱盐方法 ,不仅可提高丝素蛋白粉生产效率和收率 ,而且可以起到脱色的作用 ,所得丝素蛋白粉氨基酸含量与原茧丝中的相差不大。喷雾干燥所得粉末颗粒小于冷冻干燥所得粉末颗粒。采用自制脱盐装置和喷雾干燥配合制备丝素蛋白粉是简便可行的     

复合氨基酸电渗析脱盐中试研究

在复合氨基酸电渗析脱盐小试研究的基础上又进行了其中试研究,电渗析工艺条件的优化实验采用了先进的陡升法。中试实验过程着重研究了阳极室浓度（Ｃ＿＋）、阴极室浓度（Ｃ＿－）、料液室浓度（Ｃ＿ｄ）、浓缩室浓度（Ｃ＿ｃ）、浓缩室与料液室体积比（Ｖ＿ｃ／Ｖ＿ｄ）以及电流密度（Ⅰ）脱盐率（ＮａＣｌ）、电流效率、能耗（Ｐ）与生产能力（Ｗ）的综合影响,最后确定了中试脱盐工艺的最佳操作条件,同时,给出了最佳操作条件下的氨基酸变化情况。     

电渗析法进行胱氨酸母液脱盐的研究

猪毛酸解提取胱氨酸后的母液中含有十七种氨基酸。本文报道了采用我校由辐射法制备的高性能离子交换膜（ＨＦ－１及ＨＦ－２）,通过电渗析技术对母液进行脱盐并制得混合氨基酸。该技术已运转近一年,脱盐率＞９５．５％,氨基酸中人体必须氨基酸达２０％以上。     

血清苯丙氨酸的纸层析测定法

本文报告一种改进的纸层析法,其原理为先将血清去蛋白质并脱盐,然后进行层析。溶剂系统为正丁醇:甲酸:水(15∶3∶2)。所得结果清晰,斑点也较集中。适用于苯酮尿病的诊断和随访;并可用于筛选,由于先天性代谢缺陷而引起的氨基酸代谢障碍和诊断,由于肾小管功能缺陷(先天性或后天性)所形成的氨基酸尿。     

花花柴脱盐能力及脱盐结构研究

通过定位测试和电镜观察等方法,研究了花花柴的脱盐能力及脱盐结构,证实花花柴有极强的脱盐能力。生长第一年能使土壤全盐降低52％～56％,第二年降低80％左右,使0～40cm土壤含盐量降到1％以下,基本达到复耕水平。其脱盐机理与它结构上有泌盐腺、泌盐孔、特殊的表皮收集细胞和活跃的离子跨膜运输等密切相关。可以认为,花花柴是改良内陆盐渍环境优良的先锋植物。     

种植碱蓬可使盐性上壤脱盐

种植碱蓬可使盐性上壤脱盐我国耕地中大约有一亿亩为盐碱地,大部分集中于黄淮海平原,盐碱地的综合治理主要以工程技术和生物措施为手段,其中生物措施一项是治理盐碱地的重要环节之一。经研究发现,种植碱蓬可使盐性土壤脱盐,从而起到改良土壤的作用。碱蓬（Ｓｕａｅｄ...     

胎肝细胞中一个刺激蛋白激酶C的胰岛素介体

经胰岛素处理的人胎肝细胞,经酸性抽提,热处理,活性炭吸附,阴离子AG1×8柱pH梯度洗脱,Sephadex G10脱盐、C18疏水层析。二次薄层层析分离,得到一个对蛋白激酶C有刺激作用的活性物质。组成分析结果显示,该物质含Ser,Ala,Gly,Yal,Gln五种氨基酸和甘露糖、肌醇两种单糖,质谱测出其分子量为841。该活性物质与胰岛素介体有相似的性质、组成和结构,推测它可能为刺激胎肝细胞蛋白激酶C的胰岛素介体。     

L-赖氨酸·L-谷氨酸盐制备工艺的研究

本文研究了L -赖氨酸·L -谷氨酸盐制备过程中脱盐、复合、结晶等工艺对产品的收率和质量的影响。研究了工艺过程的控制方法 ,为此产品的工业化生产提供了重要的参数     

Dipeptide Absorption in Cystinuria

Absorption of a dipeptide and its constituent amino-acids has been studied by a perfusion technique in a patient with cystinuria and in a normal subject. Though the cystinuric patient was unable to absorb the dibasic amino-acid lysine in its free form, the dipeptide glycyl-L-lysine was well absorbed. Both free lysine and glycyl-L-lysine were well absorbed in the normal subject.This finding suggests that the reason that clinical malnutrition does not occur in cystinuria, despite defective intestinal absorption and heavy renal loss of dibasic amino-acids and cystine, is that these amino-acids can be absorbed in the form of oligopeptides.     

Chemotaxis by Rhizobium meliloti

Summary Chemotaxis by Rhizobium meliloti strain Ve 26 has been studied and conditions required for chemotaxis have been defined, using the Adler capillary assay technique. Several sugars and amino-acids were shown to be attractants with varying effectiveness for this organism: sugars are weak attractants (except gluconate) and amino-acids are good attractants (except unpolar amino-acids).     

The Uptake of Amino-Acids and their Incorporation into the Proteins of Excised Barley Embryos

Methods are described by which barley embryos may be excisedand grown under sterile conditions on a medium containing sucrose,minerals, and a complete mixture of amino-acids. Growth underthese conditions was comparable with that of intact seedlingsand the uptake of sugar and amino-acid could be studied withoutdisturbing the metabolic steady state. Purified preparationsof the embryo proteins have been made and the constituent amino-acidsseparated. ¹⁴C labelling in these amino-acids was determinedby a new gas-scintillation method. In an isotopic competitionexperiment embryos were grown in ¹⁴C-sucrose with nitrate oran amino-acid mixture as nitrogen source. The presence of exogenousamino-acids suppressed the incorporation of carbon from carbohydrateinto amino-acid residues of the embryo protein. The degree ofsuppression varied, being undetectable for glutamic acid butalmost complete for lysine and leucine; it appeared to be relatedto the length of the synthetic pathway from carbohydrate tothe amino-acid. The evidence suggested that amino-acids areprotein precursors, and this conclusion was confirmed in furtherexperiments in which ¹⁴C-aspartic acid, -glutamine, -proline,-leucine, or -lysine were supplied singly in a complete mixtureof amino-acids. The ¹⁴C was found predominantly in the amino-acidresidue of protein corresponding to the ¹⁴C-amino-acid supplied,with smaller amounts in other amino-acids of the same or relatedfamilies. Aspartic acid and glutamine yielded appreciable quantitiesof respiratory carbon dioxide, although the contribution wassmall compared to that of sucrose. Little carbon was lost ascarbon dioxide from leucine or lysine. The results are discussedin relation to the role of amino-acids in protein synthesis,and to the existence of feedback control in the amino-acid metabolismof higher plants.     

On the pathogenesis of diphtheria

Summary By means of the paper-chromatographic method an attempt was made to gain an insight into the excretion of amino-acids in the saliva of adult men and women. The amino-acids in this saliva were separated from accompanying obstructives (mucines, proteins, etc.) by dialysis through cellophane membranes. The fairly large quantities of salts were removed by electrolysis. We obtained “twodimensional chromatograms”, phenol and a mixture of collidine and lutidine having been used as solvents. With respect to the above-mentioned excretion of amino-acids in the saliva of 50 adult men and 50 ditto women, there were notable differences between the sexes. On the whole, the examined saliva samples of the women presented a fairly uniform picture. Only one amino-acid pattern showed more than 10 amino-acids. Among the 50 men, on the other hand, there were 10 cases where the examined saliva samples contained from 11 to 15 amino-acids. Quantitatively, too, a distinct difference between the sexes could be demonstrated. With the exception of valine and taurine, the men excrete larger quantities of all the amino-acids in their saliva, than the women whose saliva was examined. Part I:A. Tasman andL. Smith, Antonie van Leeuwenhoek19, 135, 1953.     

Insulin and Amino-acid Regulation of Polysomes in Perfused,Diabetic Rat Liver

IN normal mammalian liver, protein synthesis and concomitant polyribosome assembly are controlled by amino-acids^1–4. A similar control may be exerted by insulin in liver⁵ and muscle⁶. Both the effect of amino-acids on liver and that of insulin on muscle can be demonstrated with isolated, perfused tissue^4,7, but the interrelationship between these agents has not been clarified either in liver or in muscle. We have used perfused livers from diabetic rats to establish whether amino-acids and insulin promote polysomal assembly independently or in concert.     

Relationship between Serum Gold Content and Distribution to Serum Immunoglobulins and Complement<Superscript>*</Superscript>

A protein, which consists of a defined sequence of amino-acids, can be converted into another protein of equal length by changes in the sequence of nucleotides in the segment of DNA by which it is coded. It is convenient to term this segment a gene. Most proteins are 200–400 amino-acids long, so that most genes, if defined in this way, are represented by 600–1,200, or about 10³, nucleotides. The evolution of protein molecules may appear to be limited by the need for each step in the sequence to be at a selective advantage. Maynard Smith¹ has compared this with a word game in which, using exclusively meaningful words, one word has to be changed to another by altering one letter at a time.     

Proteins and insulin release: A dual role of amino-acids and intestinal hormones

In two subjects concurrent infusion of amino-acids and the hormones secretin and pancreozymin provoked much higher plasma insulin levels than did administration of amino-acids or hormones individually. It is suggested that this may be a physiological phenomenon, augmenting the release of insulin from the pancreas after a meal containing protein.     

Synthesis of orthogonally protected azahistidine: application to the synthesis of a GHK analogue

The synthesis of various orthogonally protected azahistidine derivatives are obtained via 1,3-dipolar cycloaddition reactions. The newly obtained amino-acids can be selectively deprotected either at the side chain or at the N-terminus of the amino acid and should thus allow the use of these derivatives in (solid phase) peptide synthesis.     

Active Absorption of Amino-acids in the Rectum of the Desert Locust (<Emphasis Type="Italic">Schistocerca gregaria</Emphasis>)

ALTHOUGH the concentration of amino-acids in the haemolymph of insects is high compared with that in most other groups of animals, there has been no rigorous demonstration that amino-acids are actively transported across any membrane system within the class Insecta. Treherne¹ established that ingested amino-acids are absorbed largely in the midgut of the desert locust by simple diffusion down a concentration gradient created by absorption of water and ions and Ramsay² concluded that the high concentrations of amino-acids in the secretion of the Malpighian tubules of the stick insect were the result of passive diffusion across the tubular epithelium. Because most of the water and essential solutes secreted by the Malpighian tubules are reabsorbed in the rectum of most insects³, selective retention and regulation of haemolymph amino-acids seem likely^2,4–6. Evidence for active reabsorption of amino-acids in the rectum has been sparse and inconclusive^1,2,5.     

Periodic Studies of the Proteins, Peptides, and Free Amino-Acids in Enteromorpha prolifera f. capillaris and Ulva lactuca var. rigida

The technique of circular paper chromatography was used in theanalysis of free amino-acids and amino-acid constituents ofproteins and peptides in Enteromorpha prolifera f. capillarisand Ulva lactuca var. rigida collected from Bombay at fortnightlyintervals. The amino-acids present in the proteins at different stagesof algal grwoth remained the same; but quantitative variationsin composition were usually observed, and these were independentof the age of the plant. Significant quantitative and qualitative variations were observedin the amino-acids of the peptides and in the free state, butvariations were usually independent of the age of the plant.However, in Enteromorpha prolifera f. capillaris, leucine(s),proline, and valine in the peptides, and serine in the freestate were found to increase with the age of the plant. Of the amino-acids recorded in the proteins, homocystine wasnot found in the peptide hydrolysates or among the free amino-acids.Tryptophan was absent from the peptides. Cysteric acid was foundin the peptides and in the free state, and asparagine in thefree state only.