Structure-activity relationships of anti-HIV-1 peptides with disulfide linkage between D- and L-cysteine at positions i and i+3, respectively, derived from HIV-1 gp41 C-peptide

The constrained alpha-helical structure of a C-peptide is useful for enhancing anti-HIV-1 activity. The i and i+3 positions in an alpha-helical structure are located close together, therefore D-Cys (dC) and L-Cys (C) were introduced at the positions, respectively, to make a dC-C disulfide bond in 28mer C-peptides. Accordingly, this study tested whether a dC-C disulfide bond would increase the alpha-helicity and anti-HIV-1 activity of peptides. A C-peptide can be divided into three domains, the N-terminal hydrophobic domain (HPD), middle interface domain (IFD), and C-terminal hydrogen domain (HGD), based on the binding property with an N-peptide. In general, the dC-C modifications in HPD enhanced the anti-HIV-1 activity, while those in IFD and HGD resulted in no or much less activity. The modified peptides with no activity clearly showed much less alpha-helicity than the native peptides, while those with higher activity showed an almost similar or slightly increased alpha-helicity. Therefore, the present results suggest that the introduction of a dC-C bridge in the N-terminal hydrophobic domain of a C-peptide may be useful for enhancing the anti-HIV-1 activity.

Generation and characterization of a monoclonal antibody with high species-specificity to Schistosoma japonicum glutathione S-transferase

No abstract available.

Identification and cDNA Cloning of the Leptin Receptor Long from ( OB-Rb ) from Rat Splenocytes / 대한면역학회지

No abstract available.

A Study of Surface Physical Properties of New Surfactant Using Synthetic Peptides of Surfactant Protein-B

PURPOSE: To produce a new generation of artificial pulmonary surfactant(PS), surfactant protein (SP)-B from human PSwas isolated, and the amino acid sequences of these proteins were studied. Artificial peptides of human SP-B were synthesized. New artificial PS preparations which were cornposed of phospholopids and two artificial synthetic SP-B peptides were made, and the surface physical properties of these new PS preparations were tested. METHODS: The purities of SP-B were assessed by SDS-polyacrylamide gel and the amino acid sequences of these proteins were determined. We synthetized two peptides SP-1 and SP-2 and the amino acid sequences were as follows,' SP-1: RMLPQLVCRLVLRCSMD, SP-2: RMLP- QLVCRLVLRCSM. Surface physical properties of newly artificial PSs, which were composed of a mixture of phospholipid(PL) and SP-1 or SP-2(sample A; PL+SP-1, sample B; PL+SP-2), were measured by surface spreading, adsorption rate, and surface tension-area diagram. RESULTS: The amino acid sequence of human SP-B was obtained. We produced the artificial peptides of SP-B and prepared the new generation PS(sample A and sample B). The order of the superiority of spreading and adsorption rate was Surfacten

Comparison of in vitro Surface Physical Properties of Four Artificial Exogenous Pulmonary Surfactant Preparations

PURPOSE: We conducted this study to compare the surface physical properties of four commercial preparations of artificial exogenous pulmonary surfactants in vitro which have been used in both the prevention and treatment of respiratory distress syndrome in newborn infants. METHODS: We tested four surfactants : a) Surfacten (Tokyo Tanabe, Japan) and Newfactan (Yuhan, Korea) : reconstituted bovine lung extract, b) Curosurf (Cheisi, Italy) : porcine lung mince; chloroform-methanol extract; liquid-gel chromatography, and c) Exosurf (Wellcome, USA), synthetic surfactant composed of colfosceril, palmitate, hexadecanol, and tyloxapol. We measured the surface adsorption rate, spreading rate, and surface tension(ST)-area diagram by using modified Wilhelmy balance and minimum(min-ST) and maximum ST(max-ST) by Pulsating Bubble Surfactometer. RESULTS: The adsorption rate of Surfacten is less than 30mN/m and those of Newfactan, Curosurf, and Exosurf are more than 30mN/m. The spreading rate of Surfaten and Newfactan are less than 30mN/m, and those of Curosurf and Exosurf are more than 30mN/m. The min-ST of Surfacten and Newfacten are less than 10mN/m, and those of Curosurf and Exosurf are more than 10mN/m. According to high performance of surface physical activities, which are compared with in vitro criteria of effective artificial surfactant, they are as follows; Surfacten>Newfactan>Curosurf>Exosurf. CONCLUSION: There are some differences between the surface physical properties of the four surfactant preparations. The natural surfactants appear to be superior to synthetic surfactant in vitro. Among the natural surfactants, Surfacten showed the best surface physical activities of spreading, adsorption and ST-lowering properties.

Preparation and in vitro Physical Activities of Crude Natural Surfactant and Artificial Pulmonary Surfactant Containing Synthetic Peptide and Phospholipid Mixtures

PURPOSE: In this study, natural pulmonary surfactant was extracted from bovine lung lavage and its surface activity was determined. To investigate the usefulness of synthetic peptides reconstituted with phospholipid as artificial surfactant, truncated peptides from surfactant protein (SP)-B were synthesized and restored the surface tension lowering activities when appropriately recombined with phospholipid. METHODS: Crude natural surfactant (CNS) was isolated from lung lavage by centrifugation and organic solvent for the extraction of pulmonary surfactant was selected to satisfy the in vitro physical properties. Two truncated peptides derived from C-terminal end of bovine SP-B hydrophobic protein were selected and synthesized. To prepare artificial surfactant, synthetic peptides was added to the phospholipid mixture. The various surfactant mixtures were assayed for in vitro physical activity with the Wilhemly plate method and were determined by surface spreading rate, surface adsorption rate and surface tension-area diagram. RESULTS: CNS-chloroform methanol (CM) displayed efficient surface activity compared with clinically used Surfacten but CNS-BuOH did not. The artificial surfactants containing phospholipid mixture and synthetic peptide were analyzed for their surface activities and displayed significant surfactant properties. CONCLUSION: 1-Butanol or CM (3:1) was used as an extraction solvent for CNS. CNS-CM showed more efficient surface activity than CNS-BuOH. Two synthetic peptides composing artificial pulmonary surfactant were designed and mixing ratio of peptide and phospholipid was established. Artificial surfactant dispalyed weaker surface activity than natural surfactant but significant surfactant activity.

Cloning and Nucleotide Sequence Analysis of HLA - DRA * 0101 and DRB1 * 0405 Alleles / 대한면역학회지

No abstract available.

Surfactant Protein SP-A, B, and C: Purification and Biochemical Characterization

PURPOSE: Several kinds of exogenous pulmonary surfactants (SF), either synthetic or animal- derived, are being used for the replacement therapy in respiratory distress syndrome (RDS) of newborn, especially in premature infants, and improved the neonatal mortality and morbidity. Because synthetic preparations are lack of surfactant protein (SP) and animal-derived preparations cause immunogenecity of heterogenous SP, there have been great necessity for the development of next generation of exogenous SF which made by new technology to produce new type of human SF (contained human synthetic SP). There are two methods to make next generation of SF (mixtures of phospholipids and human synthetic SP) which are using of recombinant SP or synthetic peptides of SP. For the synthesis of SP peptides and production of next generation of SF, at first step, we have isolated SP-A, B, and C from bovine lung SF, and studied the biochemical properties of these proteins. METHODS: Crude natural surfactant (CNS) and purified natural surfactant (PNS) were isolated from materials which extracted from the bovine lung lavage. The hydrophilic SP-A was purified from PNS by method of modified Hawgood, and hydrophobic SP-B, C were purified by Sephadex LH 60 column chromatography. The purities of the purified SP-A and SP-B, C were assessed by 12% SDS-polyacrylamide gel and tricine buffer SDS-polyacrylamide gel, respectively and the N-terminal amino acid sequences of these proteins were determined using Beckman PI-2090. The polyclonal anti-serum against SP-A was prepared by immunization of the purified SP-A into the mouse and the immunization of the purified SP-A into the mouse and the immunogenecity of SP-A was confirmed by indirect ELISA. RESULTS: Total 22 gm of CNS, 11 gm of PNS, and 2.5 mg of SP-B and 3.2 mg of SP-C/ 1 gm of CNS, were purified from one bovine both lungs. The molecular weights of SP-A, B, C shown in SDS-polyacrylamide gel were as follows; 28,000-35,000 Da (molecular weight) of SP-A, 15,000-18,000 Da of SP-B, 3,500-5,000 Da of SP-C. The partial N-terminal amino acid sequences of each SPs were; Leu-Glu-His-Asp-Val-Lys- Glu-Val-.... in SP-A, Phe-Pro-Ile-Pro-Ile-Pro-Tyr-.... in SP-B, Leu-Ile-Pro-.... in SP-C, respectively. These results indicated that the amino acid sequences of bovine SPs were different from those of other species, i.e., human, dog and rat, which were reported previously by another investigators and species-specific patterns were shown. The immunogenecity of the purified SP-A was confirmed by the production of polyclonal antibody against mouse. The polyclonal antibody of SP-A could be used for measuring the amount of pulmonary SF in lung lavages. Carbohydrate portion of SP-A was cleaved with N-glycocisidase F. This result suggested that carbohydrate group could be N-glycosylated in some arginine residue of SP-A. CONCLUSIONS: The SP-A, B, C were purified from bovine lung SF, and N-terminal amino acid sequences of each SP-A, B, C were determined. Further studies were needed for the development and use of next generations of exogenous SF preparation, which based on synthetic SP-peptides, for the treatment of neonatal RDS in the future.