Amino Acids, Peptides, and Proteins Commons^™

Signal Transduction In Bacterial Chemotaxis, Edward Heath Rowsell

Loma Linda University Electronic Theses, Dissertations & Projects

This study investigated the site of ATP utilization in the signal transduction pathway of bacterial chemotaxis and localized the point of convergence of a methylation-independent system of chemotaxis with the methylation-dependent system. The identity of the signal originating from the phosphotransferase system was investigated by substituting the fructose-inducible HPr-like protein FPr for HPr in transport and chemotaxis. In addition, a novel chemoattractant, glycerol, was identified for Salmonella typhimurium. Histidine-auxotrophic S. typhimurium strains ST23 (hisF) and ST171 (hisF cheB) were depleted for ATP. The times required for the bacteria to adapt to a step increase in serine, …

Aerotaxis In Bacillus Subtilis, Laurence Samuel Wong

Loma Linda University Electronic Theses, Dissertations & Projects

B. subtilis, like Escherichia coli and Salmonella typhimurium, responded to a step increase in oxygen concentration by swimming smoothly (~ 35 s duration) and to a decrease in oxygen by tumbling. In a spatial gradient of oxygen in liquid media, a band of cells congregated near the air interface. Aerotaxis required a functioning respiratory chain. Adaptation of B. subtilis, E. coli and S. typhimurium to media containing amino acids requires methylation of receptors/methyl-accepting chemotaxis proteins. Adaptation to oxygen and phosphotransferase sugar substrates in B. subtilis was dependent on methylation, unlike similar adaptation in E. coli and S. typhimurium. …

Separation And Quantification Of Queuine-Modified And Unmodified Transfer Rna Isoacceptors, Jorge Miguel Pereira De Oliveira Da Silva Santos

Chemistry & Biochemistry Theses & Dissertations

The discovery of a base-exchange modification in the first position of the anticodon of four transfer RNA (tRNA) isoacceptor families has been shown to be correlated with a decrease in the rate of cell division in several tumorigenic tissues. This fact led to the hypothesis that wobbling in the anticodon might be a control point wich mediates the rate of translation. A suitable method for separation of different tRNA isoacceptor families had to be created in order to generate a means for quantitatively measuring degrees of this base modification in tRNA. Radio labelled amino acids were used to charge tRNA …

High Performance Liquid Chromatographic Separation Of Different Types Of Collagen, Yongjoo Chung

Chemistry & Biochemistry Theses & Dissertations

The objective of this research was to develop a method for the separation of different types of collagen using a large pore size (100 nm) reversed-phase C-8 column. Three different types of collagen (type I, III, and V) were sufficiently separated on the column using a mobile phase containing water-acetonitrile-trifluoroacetic acid. Collagens found in each HPLC peak were identified using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) to assay the column effluents.

Trifluoroacetic acid (TFA) was used as an ion pair reagent. This compound improved the chromatographic profile for these proteins on a reversed-phase column. It was observed that with …

Activation In Vitro Of Transfer Rna-Guanine Ribosyltransferase By Protein Kinase C, Panayota Eriotou

Chemistry & Biochemistry Theses & Dissertations

The purpose of this study was to isolate and purify the enzymes, transfer RNA-guanine ribosyltrasferase and protein kinase C, and to determine whether the phosphorylating enzyme activates the insertion enzyme in vitro. Transfer RNA-guanine ribosyltransferase lost activity within several days after isolation and total, complete reactivation was accomplished in the presence of protein kinase C. This demonstrated that ribosyltransferase's instability is related to the degree of its phosphorylation. It is proposed that modification of tRNA is controlled by protein kinase C. Deactivation of the insertion enzyme leads to hypomodified tRNA which in turn is associated with neoplasia. Potential use …

Laminin Potentiates Differentiation Of Pcc4uva Embryonal Carcinoma Into Neurons, T. M. Sweeney, Roy C. Ogle, C. D. Little

School of Medical Diagnostics & Translational Sciences Publications

The embryonal carcinoma PCC4uva differentiates into neurons in response to treatment with retinoic acid and dbcAMP. We used this in vitro model system to study the effects of laminin on early neural differentiation. Laminin substrata markedly potentiate neural differentiation of retinoic acid and dbcAMP-treated cultures. Only laminin induced more rapid neural cell body clustering, neurite growth and neurite fasciculation as compared to type IV collagen, type I collagen, and fibronectin substrata. Exogenous laminin substrata promoted greater cell attachment, cellular spreading and growth to confluence than type IV collagen, type I collagen, fibronectin and glass substrata. Laminin-induced effects were inhibited by …

Regulation Of Queuine Insertion Into Transfer Rna: Effects Of Tumor Promoters, Bonnie Jean Brooks

Chemistry & Biochemistry Theses & Dissertations

The purpose of this study was to treat normal human fibroblasts with known tumor promoters and observe queuine modification of tRNA. The queuine insertion enzyme, tRNAguanine ribosyltransferase, was studied in vivo and in vitro. Tumor promoter-treated human fibroblast cultures exhibited variable queuine-insertion rates with a transient inhibition that correlated with variable levels of queuine modified tRNA over time in culture from passages 3 — 8. In contrast the in vitro studies showed that phorbol cetera and saccharin actually increased insertion with strong evidence indicating phosphorylation as a positive modulating force of the enzyme activity. It is proposed that chronic stimulation …

Collagen Binding Proteins Derived From The Embryonic Fibroblast Cell Surface Recognize Arginine-Glycine-Aspartic Acid, Roy C. Ogle, Charles D. Little

School of Medical Diagnostics & Translational Sciences Publications

Several cell surface proteins (Mr = 120,000, 90,000, 63,000 and 47,000) apparently integral to embryonic fibroblast plasma membranes were extracted with detergent and isolated by collagen affinity chromatography. Certain of these proteins (Mr = 120,000, 90,000, and 47,000) were specifically eluted from collagen affinity columns by synthetic peptides containing the amino acid sequence arginyl-glycyl-aspartic acid (RGD). These data show that a number of collagen binding proteins exist on the embryonic fibroblast cell surface. Some of the proteins may be collagen receptors binding to RGD sequences in the collagen molecule while at least one of the proteins (Mr = 63,000) recognizes …

Isolation And Partial Characterization Of Basic, Sperm-Specific, Nuclear Proteins In The Dog And Hampster, Richard William Hall

Biological Sciences Theses & Dissertations

The purpose was to determine whether dogs and hamsters contain the same sperm-specific protamine and testis specific proteins (TP) as other eutherian mammals previously studied. The proteins (protamine and TPs) were isolated from spermatids and mature spermatozoa, and were subjected to electrophoresis in an acid-urea, polyacrylamide gel system according to the procedure of Panyim and Chalkley (1962). The results indicated that, regardless of the anatomical location of sperm acquisition, acid precipitation technique, or denaturing agents used, epididymal and testicular samples from both the dog and hamster contained protamine in elongated spermatids and mature spermatozoa. The protamines from dogs and hamsters …

An Analysis Of Protein-Ligand Interactions For Enzyme Ii-Mannitol From Escherichia Coli, Brent Lee Wood

Loma Linda University Electronic Theses, Dissertations & Projects

Enzyme II^mtl of Escherichia coli was purified from mtlA-overexpressing E. coli strain LJ1112 extraction of isolated membranes with deoxycholate, followed by hexyl agarose and ω-amino hexyl agarose chromatography in Lubrol PX. A 10-fold increase in total pure protein and 2.5-fold increase in specific activity over previously reported procedures was obtained. Tryptic fragments of Enzyme II^mtl were also purified and identified as the membrane and cytoplasmic domains by protein sequencing and SDS-PAGE. The fluorescence spectrum of Enzyme II^mtl suggested that two populations of tryptophan residues existed with emission maxima at 322 and 344 nm, corresponding to buried …

Laminin Receptors For Neurite Formation, H. K. Kleinman, Roy C. Ogle, F. B. Cannon, C. D. Little, T. M. Sweeney, L. Luckenbill-Edds

School of Medical Diagnostics & Translational Sciences Publications

Laminin, a basement membrane glycoprotein promotes both cell attachment and neurite outgrowth. Separate domains on laminin elicit these responses, suggesting that distinct receptors occur on the surface of cells. NG108-15 neuroblastoma-glioma cells rapidly extend long processes in the presence of laminin. We report here that 125I-labeled laminin specifically binds to these cells and to three membrane proteins of 67, 110, and 180 kDa. These proteins were isolated by affinity chromatography on laminin-Sepharose. The 67-kDa protein reacted with antibody to the previously characterized receptor for cell attachment to laminin. Antibodies to the 110-kDa and 180-kDa bands demonstrated that the 110-kDa protein …

The Synthesis And Evaluation Of The Cardiovascular Activity Of Novel Imidazole Ring Systems, Joseph E. De Los Angeles

Chemistry & Biochemistry Theses & Dissertations

An investigation was undertaken to synthesize and evaluate the cardiovascular activity of two imidazole ring systems. Imidazoles with hypotensive activity would provide novel potential antihypertensive drugs. These novel structures may also find use as chemical probes in the study of the cardiovascular system and as prototypes for other potential cardiovascular agents.

The histamine derivative, 7,7-dipyridyl-4,5,6,7-tetrahydroimidazo-[4,5-c]pyridine (ligand l), was demonstrated to possess significant hypotensive activity in laboratory rats. A 15 mg/Kg dose of ligand 1 produces a statistically significant decrease in blood pressure when injected IP. This hypotensive effect is also associated with marked increase in heart rate. Although compound 1 …

An Immunochemical Analysis Of Alcoholic Hyaline And Its Relationship To Keratin Intermediate Filaments, David L. Drexler

Loma Linda University Electronic Theses, Dissertations & Projects

Alcoholic Hyaline (AH) and keratin intermediate filaments possess ultrastructural, biochemical and immunochemical similarities. This study compares human AH, human stratum corneum keratin (HSCK) and normal human liver cytokeratin (HCK) by quantitative immunochemical means, using polyclonal as well as monoclonal antibodies. Enzyme-linked immunosorbent assays (ELISAs) were employed, as well as "immunoblotting" and immunocytochemical techniques. HCK was isolated using Triton X-100 and "high-salt” buffers and exhibited seven major polypeptide bands on SDS-PAGE (41-58 kd). Antisera were made toward HCK and the two major HCK bands. Other immunochemicals included antisera toward AH, the three major AH bands, and HSCK, as well as 3 …

The Relationship Of Vitamins B-6 And B-12 To Plasma Homocysteine Levels In Men At Low- And High-Risk For Coronary Heart Disease, Marlene E. Swift

Loma Linda University Electronic Theses, Dissertations & Projects

There is evidence that homocysteine may be a factor in increasing the risk of coronary heart disease (CHD). To explore this relationship further, we assessed the interrelation of dietary vitamins B-6, B-12 and folate, and plasma pyridoxal-5'-phosphate and vitamin B-12 with plasma free and protein-bound homocysteine levels. Fasting blood and three-day dietary records were obtained from nine men low-risk (LR) and five at high-risk (HR) for CHD. The HR mean systolic blood pressure, total cholesterol (TC), and TC/cholesterol ratios were significantly higher than LR levels. Groups were comparable by age, weight, height, skinfolds, exercise, and smoking history. No significant difference …

Lectins, El-Nasir Lalani, M Wells

Department of Pathology and Laboratory Medicine

No abstract provided.

Two-Dimensional Electrophoretic Studies Of Normal Spematozoal Proteins, Ying Lin

Chemistry & Biochemistry Theses & Dissertations

Protein profiles of human spermatozoa have been mapped by using high resolution two-dimensional electrophoresis which combines isoelectric focusing as the first dimension and polyacrylamide gradient gels electrophoresis in SDS as the second dimension. The profiles of normal spermatozoa! extraction, acrosomal extraction and seminal plasma showed high resolution in its separation capability. No qualitative or quantitative differences were observed by using Coomassie Brilliant Blue R-250 staining in a much higher concentration of proteins. However, coomassie blue lacks the sensitivity to detect many minor components. Therefore, a silver staining procedure was used, which resulted in greatly increased sensitivity.

Samples from normal fertile …

A Method For The Comparison Of Hdl Containing Apoprotein E And Hdl Cholesterol, Steven A. Knizner

Chemistry & Biochemistry Theses & Dissertations

Human serum high density lipoproteins (HDL) were isolated by preparative salt density gradient ultracentrifugation and analyzed further by heparin-sepharose affinity chromatography. Separation of the major classes of serum lipoproteins was achieved after a single ultracentrifugation on a salt density gradient at 272,000 x g for 36 hours in a swinging bucket rotor. After isolation, the total HDL was subdivided into HDL containing apoprotein E and HDL without this apoprotein by heparin-sepharose affinity chromatography. Relative amounts of these subclasses were then calculated.

HDL-cholesterol was measured after precipitation of LDL and VLDL by phosphotungstic acid and magnesium. The statistical relationship between HDL …

Evaluation Of Peptide Assimilation In Ehrlich Ascites Tumor Cells, John M. Castellano

Biological Sciences Theses & Dissertations

The dipeptides glycyl-L-(³H)-leucine and L-phenylalanyl-L-(³H)-leucine were synthesized in radioactive form and utilized in the analysis of peptide transport and hydrolysis by Ehrlich ascites tumor cells. The tumor cells were cultured in the abdominal cavity of CF-1 albino mice and harvested into sterile isotonic buffer for all experimental analyses.

The results of this study reveal that the tumor cells rapidly accumulate radiolabel when incubated with the above mentioned peptides, but that the peptide is most probably hydrolyzed extracellularly and free L-(³)-leucine transported. This hypothesis is based on the observations of reduction in accumulation of radiolabel …

High Resolution Two Dimensional Electrophoresis Of Soluble Proteins In Human Spermatozoa, Hsing-Ying Liu

Chemistry & Biochemistry Theses & Dissertations

The evaluation of human semen is very important for diagnosis of male infertility. Combined with the analysis of seminal plasma, a comprehensive biochemical screening of human spermatozoan proteins may be of assistance in providing qualitative and quantitative information to the physician to assist with evaluation.

In this study, human spermatozoa were ruptured by sonication. The soluble spermatozoan proteins were separated from the cellular debris by centrifugation and then analyzed in dissociated forms by two dimensional electrophoresis. The separated proteins were visualized by a silver stain method.

It has been shown that these combined techniques can resolve- four to five hundred …

Conformational Analysis Of Nonsteroidal Estrogen Analogs, Robert N. Spady

Loma Linda University Electronic Theses, Dissertations & Projects

In target tissue, estrogens initiate a series of events, ending in protein synthesis, by binding to a cytoplasmic receptor. Once the estrogen binds, the receptor complex is activated--a process including dimerization of the estrogen complex with another subunit. In order to study the possible receptor-ligand interactions, conformational analysis was performed on several nonsteroidal estrogen analogs, using the CAMSEQ8 molecular mechanics program.

The probability that a molecule will exist in a given conformational energy well depends both on the energy and the shape of the well. A method has been previously worked out to calculate probabilities using both of these variables, …

Development Of A Procedure For Analysis Of High Density Lipoprotein Subclasses, Chan Chin

Chemistry & Biochemistry Theses & Dissertations

Human serum high density lipoprotein subclasses, HDL₂ and HDL₃ , were isolated by preparative salt density gradient ultracentrifugation and further analyzed by electrophoresis on a 4 to 15% concentration gradient polyacrylamide gel.

The separation of the major classes of serum lipoproteins was achieved after a single ultracentrifugation for 272,000 g at 15°c in a swinging bucket rotor. High resolution concentration gradient gel electrophoresis was found to be particularly suitable for the separation of lipoproteins. The isolation of HDL by precipitation methods, heparin-manganese and dextran-magnesium have also been evaluated in this study, and were found not to completely separate …

High Resolution Two-Dimensional Electrophoretic Study Of Human Seminal Plasma Proteins, Edward E. Gaunt

Chemistry & Biochemistry Theses & Dissertations

A comprehensive biochemical screening procedure for the evaluation of seminal plasma constituents is needed which, when used in conjunction with semen analysis, can provide the physician with both qualitative and quantitative information regarding the fertility status of an individual.

High resolution two-dimensional electrophoresis is a technique whereby proteins in a complex mixture such as a biological fluid are separated in one dimension by molecular charge and in the second dimension by molecular mass. It has been the purpose of this investigation to adapt and evaluate this technique for the analysis of human seminal plasma.

Our efforts have shown that this …

Sulfatides As Opiate Receptors: An Evaluation Of The Opiate Binding Potential Of Sulfogalactosylgylcerolipid, Darby Geoghegan Hand

Chemistry & Biochemistry Theses & Dissertations

Cerebroside sulfate (CS) has recently been shown to bind opiate drugs in a pharmacologically relevent manner and therefore satisfy the structural requirements of an opiate receptor. Seminolipid (SGG), a novel sulfated galactosyl. glycerolipid that has been isolated from the testes of a variety of mammals, may be viewed as a structural analog of CS. In view of this structural similarity, it is reasonable to presume that SGG may also bind opiate drugs. The isolation of SGG from boar testes was accomplished using silica gel dry column chromotography with a chloroform: methanol water solvent system. The structure and purity of the …

Some Supplementary Studies With Wheat Proteins, Gerald G. Porter

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract Not Included]

Introduction The importance of selecting only foods containing proteins of high nutritive value has been somewhat over-emphasized in the past because of the failure to recognize the possibility of supplementary relationships among proteins that are not of high quality. Hart (11) has wisely suggested that a food should not be relegated to an inferior class because its proteins, when fed alone, are not of high biological value. Sherman (31) has reminded us that with a knowledge of the nutritional chemistry of the proteins of various foods, it becomes relatively easy to utilize their supplementary relationships so that …