Effects of source and level of dietary lysine on growth performance of pigs from 24 to 48 lb

Three hundred twenty, 24 lb nursery pigs were fed for 19 days to compare the effects of increasing dietary lysine from L-Iysine HCl (L-Lys) or Peptide Plusâ„¢ (PP) on growth performance. Three dietary treatments (1.025, 1.15, and 1.275% lysine) were each formulated with L-Lys and PP. Negative and positive control corn-soybean meal-based diets were formulated to .90 and 1.275% lysine, respectively. Increasing dietary lysine to 1.275% from L-Lys or PP resulted in increased performance; however, pigs fed the positive control diet had the best overall performance.; Swine Day, Manhattan, KS, November 18, 199

Effect of maternal lysine supplementation on the performance of growing rabbits. Preliminary results

The experiment studied the effect of dietary lysine supplementation to rabbit does on the performance and on meat's protein and lysine content of their offspring. Half of the does (n=43) fed control diet (C; Lys: 0.68%), while the other half a lysine supplemented diet (L; Lys: 0.80%) from 3 days before AI until weaning. After kindling, half of the litters of C does were put under C does, while the other half under L does. The same procedure was followed for offspring of L does. After weaning, rabbits fed the same diet (0.68% Lys). Does' dietary treatment significantly affected the weaning weight, however, only lysine supplementation during suckling age had negative effect (340 vs 315g for C and L does, respectively; P<0.01). The kit's milk intake, measured at 3rd and 7th day of age, nursed by L does was significantly lower. Other productive and carcass traits did not differ significantly

Analysis of lysine recognition and specificity of the Bacillus subtilis L box riboswitch

The ever-changing environment of a bacterial cell requires sophisticated mechanisms to adjust gene expression in response to changes in nutrient availability. L box riboswitch RNAs regulate gene expression in response to cellular lysine (lys) concentrations in the absence of additional regulatory factors. In Bacillus subtilis, binding of lysine (lys) to the L box RNA causes premature transcription termination in the leader region upstream of the lysC coding sequence. To date, little is known about the specific RNA–lys interactions required for transcription termination. In this study, we characterize features of the B. subtilis lysC leader RNA responsible for lys specificity, and structural elements of the lys molecule required for recognition. The wild-type lysC leader RNA can recognize and discriminate between lys and lys analogs. We identified leader RNA variants with mutations in the lys-binding pocket that exhibit changes in the specificity of ligand recognition. These data demonstrate that lysC leader RNA specificity is the result of recognition of ligand features through a series of distinct interactions between lys and nucleotides that comprise the lys-binding pocket, and provide insight into the molecular mechanisms employed by L box riboswitch RNAs to bind and recognize lys

Solid-state conformation of copolymers of ß-benzyl-L-aspartate with L-alanine, L-leucine, L-valine, γ-benzyl-L-glutamate, or ε-carbobenzoxy-L-lysine

The solid-state conformation of copolymers of ß-benzyl-L-aspartate [L-Asp(OBzl)] with L-leucine (L-Leu), L-alanine (L-Ala), L-valine (L-Val), γ-benzyl-L-glutamate [L-Glu(OBzl)], or ε-carbobenzoxy-L-lysine (Cbz-L-Lys) has been studied by ir spectroscopy and circular dichroism (CD). The ir spectra in the region of the amide I and II bands and in the region of 700-250 cm-1 have been determined. The results from the ir studies are in good agreement with data obtained by CD experiments. Incorporation of the amino acid residues mentioned above into poly[L-Asp(OBzl)] induces a change from the left-handed into the right-handed α-helix. This conformational change for the poly[L-Asp(OBzl)] copolymers was observed in the following composition ranges: L-Leu, 0-15 mol %; L-Ala, 0-32 mol %; L-Val, 0-8 mol %; L-Glu(OBzl), 3-10 mol %; and Cbz-L-Lys, 0-9 mol %

Enantiomeric and Diastereomeric Self-Assembled Multivalent Nanostructures : Understanding the Effects of Chirality on Binding to Polyanionic Heparin and DNA

A family of four self-assembling lipopeptides containing Ala-Lys peptides attached to a C16 aliphatic chain were synthesised. These compounds form two enantiomeric pairs that bear a diastereomeric relationship to one another (C16-l-Ala-l-Lys/C16-d-Ala-d-Lys) and (C16-d-Ala-l-Lys/C16-l-Ala-d-Lys). These diastereomeric pairs have very different critical micelle concentrations (CMCs). The self-assembled multivalent (SAMul) systems bind biological polyanions as a result of the cationic lysine groups on their surfaces. For heparin binding, there was no significant enantioselectivity, but there was a binding preference for the diastereomeric assemblies with lower CMCs. Conversely, for DNA binding, there was significant enantioselectivity for systems displaying d-lysine ligands, with a further slight preference for attachment to l-alanine, with the CMC being irrelevant

Effects of dietary supplementation of methionine and lysine on milk production and nitrogen utilization in dairy cows

ABSTRACT The effect of the content of lysine and methionine in metabolizable protein (MP) on lactation performance and N utilization in Chinese Holstein cows was determined. A control diet (C) was formulated to be adequate in energy but slightly limiting in MP. The concentration of Met and Lys in MP was 1.87 and 5.93%, respectively. The treatments were as follows (% of Met or Lys in MP): L = diet C supplemented with l-lysine-HCl at 0.49% on a dry matter (DM) basis (Met, 1.87; Lys, 7.00); M = diet C supplemented with 2-hydroxy-4-(methylthio)-butanoic acid (HMB) at 0.15% (Met, 2.35; Lys, 5.93); ML = diet C supplemented with 0.49% l-lysine HCl and 0.15% HMB (Met, 2.39; Lys, 7.10). The diets were fed to 60 Chinese Holsteins in mid-lactation (average days in milk = 120, and milk yield = 32.0 kg/d) for 8 wk. Milk yield was increased by supplementation of either Lys (1.5 kg/d) or Met (2.0 kg/d), and supplementation of both Lys and Met further increased milk yield (3.8 kg/d). There was no significant difference in dry matter intake across treatment groups. Cows on treatments M (3.95%) and ML (3.90%) had higher milk fat content than those on C (3.60%) and L (3.67%), but there were no significant differences in milk protein and lactose contents or somatic cell count among treatments. Supplementation of Met or Lys significantly increased Met or Lys concentration in arterial plasma. Treatment ML had a higher conversion of intake N to milk N and lower urea N concentrations in serum, urine, and milk than did treatment C. Supplementing HMB and l-lysine-HCl to provide approximately 2.3% Met and 7.0% Lys of the MP in diets slightly limiting in MP increased milk production, milk protein yield, and N utilization efficiency

Influence of L-Lysine as dopant in ammonium tetroxalate dihydrate– spectral, optical, thermal, mechanical and dielectric properties

Semi organic crystals offer a variety of molecular structures by virtue of the changes brought out in selection of dopants. In the present work mechanical, thermal, dielectric, FTIR and UV studies of single crystals of ammonium teroxalate dihydrate (ATOXAL) doped with basic amino acid L-Lysine have been studied and compared. Fourier transform infrared (FTIR) spectroscopy study confirms the incorporation of L-Lysine into ATOXAL. Optical studies on L-Lysine doped ATOXAL (L-Lys doped ATOXAL) crystals reveal that these crystals are optically better and more transparent than the pure ones having wide transmission spectra lying in the entire visible and near infrared (NIR) regions. Optical band gap has been found to be 4.281 eV and the nonlinear index of refraction is 1.829. Negative photoconductivity has been exhibited by the crystal. TG / DTG and DSC analyses reveal that thermal anomalies occurr at 111.1 °C and 231.8 °C. Low dielectric constant and dielectric loss at higher frequency observed in L-Lys doped ATOXAL is a desirable property to enhance the NLO efficiency. Also, it is observed from the dielectric studies that the ferroelectric phase has higher activation energy than the paraelectric phase. Vickers’s micro hardness test reveals that dopant inclusion increased the mechanical strength of the crystals

Lysine Catabolism and In Vivo Substrate Specificity of D-Amino Acid Dehydrogenases in Pseudomonas Aeruginosa PAO1

Among multiple interconnected pathways for L-Lysine catabolism in pseudomonads, it has been reported that Pseudomonas aeruginosa PAO1 employs the decarboxylase and the transaminase pathways. However, knowledge of several genes involved in operation and regulation of these pathways was still missing. Transcriptome analyses coupled with promoter activity measurements and growth phenotype analyses led us to identify new members in L-Lys and D-Lys catabolism and regulation, including gcdR-gcdHG for glutarate utilization, dpkA, amaR-amaAB and PA2035 for D-Lys catabolism, lysR-lysXE for putative L-Lys efflux and lysP for putative L-Lys uptake. The amaAB operon is induced by L-Lys, D-Lys and pipecolate supporting the convergence of Lys catabolic pathways to pipecolate. Growth on pipecolate was retarded in the gcdG and gcdH mutants, suggesting the importance of glutarate in pipecolate and 2-aminoadipate utilization. Furthermore, this study indicated links in control of interconnected networks of lysine and arginine catabolism in P. aeruginosa. Effect of D-amino acids and the genes involved in their metabolism are of great interest in both bacteria and mammals. D-Arg utilization in PAO1 requires the coupled dehydrogenases DauB and DauA. In this study, DauB was found to use only L-Arg as its substrate unlike its partner dehydrogenase DauA with wide substrate specificity. However, evidence from this study and previous studies suggest that the coupled enzymes DauB and DauA are unique for D-Arg catabolism. The three D-amino acid dehydrogenases DguA, DadA and DauA were found to have somewhat limited in vivo substrate specificity compared to that found in vitro tested using purified enzymes. Many studies showed that D-amino acids are toxic to bacteria. The ΔdguA, ΔdadA and ΔdauA triple mutant had two-fold lower minimum inhibition concentration of carbenicillin and tetracycline compared to wild-type PAO1. Both in the wild-type PAO1 and the triple mutant, synergy was observed between gentamicin or tetracycline (at concentrations below the MIC) and D-amino acids resulting in growth inhibition or reduction, respectively. However, no special synergistic or antagonistic effects were observed specifically in the ΔdguA, ΔdadA and ΔdauA triple mutant as compared to the wild-type PAO1 when D-amino acids were given in combination with antibiotics

Lysine-Grafted MCM-41 Silica as An Antibacterial Biomaterial

Abstract: A facile strategy for zwitterionization of bioceramics based on direct incorporation of L-lysine amino acid via the ε-amino group onto mesoporous MCM-41 materials is proposed. FTIR studies of lysine-grafted MCM-41 (MCM-LYS) showed simultaneously bands at 3080 and 1540 cm−1 and bands at 1625 and 1415 cm−1 corresponding to -NH3+/COO− pairs, demonstrating the incorporation of the amino acid on the material surface keeping its zwitterionic character. Both elemental and thermogravimetric analyses showed that the amount of grafted lysine was 8 wt % based on the bioceramic total weight. Moreover, MCM-LYS material exhibited a reduction of adhesion of S. aureus and E. coli bacteria in 33 and 50%, respectively at physiological pH, as compared with pristine MCM-41. Biofilm studies onto surfaces showed that lysine functionalization elicited a reduction of the area covered by S. aureus biofilm from 42% to only 5% (88%). This research shows a simple and effective approach to chemically modify bioceramics using single amino acids that provide zwitterionic functionality, useful to develop new biomaterials able to resist bacterial adhesion

Single label fluorescent derivatization of peptides

A one step method for the attachment of a single fluorescent label to peptides through their N-terminus is described. The method employs fluorescein-5-isothiocyanate as the label of choice and a lower than normal derivatization buffer pH that discriminates against $\varepsilon$-amino derivatization in favor of $\alpha$-amino derivatization provided that this group may act as an efficient nucleophile. A kinetic study was performed in order to identify the optimal derivatization buffer pH for $\alpha$-amino group selectivity, using $\rm N\alpha$-t-BOC-L-lysine and $\rm N\varepsilon$-t-BOC-L-lysine as model compounds for derivatization through $\varepsilon$-amino and $\alpha$-amino groups, respectively. The optimal pH was found to be 8.5. Six small peptides, Arg-Lys, Lys-Trp-Lys, Lys-Lys, Lys-Lys-Lys, Lys-Lys-Lys-Lys and Arg-Pro-Lys-Pro, were derivatized at pH 8.5 in an effort to corroborate the results of the kinetic study. It was found that this method of single label derivatization via buffer pH control was successful for peptides with fewer than four lysines residues