Papers by Keyword: Lysine

Abstract: Lysine doped polypeptide modified particles were chemically synthesized in different weight ratios of polypeptide to Py feed. The microstructures of these PPys were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier Transform Infrared (FTIR). Semiconductor parameter analyzer, ubbelohde viscometer and rotation viscometer were used to characterize the electrical property, viscosity and solubility of these PPys. The results show that the polypeptide has the function as the template in the Py polymerization. The lysine doped PPys form many rings with diameters of about several micrometers, with the weight ratio increase, the ring structure become more obvious and the diameters of the rings decrease to about 200 nm. The conductivity of lysine doped polypeptide modified PPys synthesized with the weight ratio of 3:1 is about 1.73 × 10^-3 S/cm. It is mostly soluble in acetic acid, good soluble in the mixture of acetic acid and HFIP with a volume ratio of 2:1. Moreover, the solubility in the mixture of acetic acid and HFIP is little affected by weight ratio and maintain about 93.8%, indicating its good solubility in no toxicity solvent or very low toxicity solvent.

Abstract: Amino acids emerged in various biochemical cycles in vivo, affecting the performance and carcass characteristics of broilers. In this study, the contents of dietary lysine and their effects on carcass performance of broiler were investigated. Experimental results showed that deficient dietary lysine significantly reduced live weight, carcass weight, eviscerated yield with gihlet (EYG) and eviscerated yield (EY) of broilers. Whereas, the percentage of slaughter yield, the percentage of eviscerated yield (PEY) and the percentage of eviscerated yield with giblet (PEG) were slightly affected. Many CpG sites were found at the myostatin exon 1 region (nucleotides 2360-2980 bp). At the myostatin exon 1 region where CpG sites enriched (nucleotides 2360-2980 bp), we found significantly lower methylation rate of 18% in low-lysine group of 55-day-old broilers, compared with methylation rate of 87% in control group, which suggested the deficient dietary lysine may lead to demethylation of their original methylated sites. In muscle tissues, the exon1 hypermethylation status of myostatin gene was detected, which was negative correlated with the expression of this gene. These results suggested that methylation of this gene was a dynamic process, which plays a dominant role in regulation of gene expression for development of individuals.

Abstract: The purpose of this study was to estimate influence of lysine for osteogenesis in the porous hydroxyapatite (HA) scaffolds with bone marrow cells. The HA scaffolds were soaked in 100mM concentration of lysine solution. They were kept in bone marrow cell suspension at 1×106 cells/ml density. Another HA scaffolds without immersion in lysine solution were kept in the cell suspension at 1×106 or 1×107 cells/ml density. They were respectively implanted into dorsal subcutis of rats for 4 weeks. Serially sectioned paraffin specimens were made and observed histologically. In several sections, total pores and ones with bone were counted. Many pores containing bone were found in1×107 cells/ml concentration group. The significant difference was between 1×107 cells/ml group, the lysine group, and 1×106 cells/ml group. Although more bone formation was seen in lysine group than in 1×106 cells/ml group. There was no significant difference between the groups. Concentration of lysine to add in culture medium or scaffold should be improved respectively.

Abstract: Success in surgical joint replacements has resulted in a huge demand amongst patients. Coupled with the lowered average age of patients requiring hip replacements, younger patients are demanding longer life expectancy from such devices. The increasing need and demand for more durable implants have led to new formulations of high performance nanomaterials (materials with basic structural units of 1-100 nm). Nanotubes in particular have shown great promise because they: 1) have sizes that approach biological structures and 2) possess efficient channels for displaying chemistries relevant to living systems at high densities and well-controlled spatial distribution. Helical rosette nanotubes (HRN) are a new class of soft organic nanomaterials composed of a guanine-cytosine building block that self-assembles in aqueous environments into stable nanotubular structures with an inner diameter of ~1.1 nm. HRN can be decorated with biologically active chemical functionalities such as cell attracting peptide fragments. Previously, we have showed that HRN coated Ti can enhance OB attachment. In addition, proteins were seen to interact favorably with HRN networks in a manner favorable toward OB attachment. Furthermore, in the absence of proteins, HRN were seen to play the role of proteins in promoting OB attachment. The studies herein, attempt to understand the role of the lysine clusters on HRN toward OB attachment. Results show that OB do respond to lysine and molecular orientation considerations were shown to be important. Detailed structural considerations from molecular modeling further present the possibility of topographical influences (nanotube network architecture) towards OB attachment.