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.

High Value-Added Peptide/Protein Materials

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

Effect of Interleukin-2 on the Surgically Induced Enndometriosis in Rat / 대한면역학회지

It has been shown that wornen with endometriosis have several immunological defects. The effect of interleukin-2 (IL-2) for the treatment of induced endometriosis in rat was studied. The results obtained are as followings: proliferation of epithelium is increased, and the inner surface is undulated with 1.5 nM IL-2. In 7.5 nM IL-2, the epithelial cells are changed to columar ones, and secretory hobs are observed at the apex of individual cell. Secretory activity of epithelium is increased with 0.5 nM IL-2, and apoptosis of the epithelial cell is observed in 15 nM IL-2. The levels of progesterone and estradiol in sera of rat were increased after treatment with IL-2 and were highest in the concentration of 1.5 nM IL-2. The results of this study can be a guide in the development of new therapeutic approaches for the treatment of endometriosis.

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.

Evaluation of Differential Antigenic Properties of Selected B - cell Epitopes from the HIV - 1 p24 Protein using Synthetic Peptides / 대한면역학회지

The gag encoded p24 protein of human immunodeficiency virus-1 (HIV-1) is a major constitutent of the viral core, and is also known as one of the most immunodominant antigens in the host immune response against the HIV-1. Based on the neutralizing ability of anti-p24 antibodies as well as their rapid appearance in human serum after viral infection, the development of vaccines and diagnostic tools targeting the p24 protein and anti-p24 antibodies is of great interest. For the characterization of the immunological properties of the HIV-1 p24 protein, in a previous study, putative B-cell epitopes were identified by screening the reactivity of a goat anti-p24 antiserum to a large array of overlapping synthetic peptides covering the whole p24 sequence. Four peptides were identified for their abilities to elicit a strong B-cell response, which sequences comprises the regions p24 (164-182), (202-221), (217-236) and (232-256), respectively. In the present study, the immunogenicity and differential properties of each of these individual epitopes were further characterized. To evaluate the time course of the antibody response, BALB/c mice were immunized with the HIV-1 p24 protein and their serum titers against each of these peptides were determined. The earliest immune response was observed against the p24 (202-221) peptide, which also showed the highest antibody titer against the immunized antigen. Furthermore,. enzyme-linked immunosorbent assay with HIV-1 p24 protein coated microtiter plates revealed that anti-p24 (202-221) antiserum has the most pronounced reactivity against the native p24 protein. Since the p24 (202-221) epitope has also been reported to include a cytotoxic T-lymphocyte epitope, it is suggested that this region might represent a powerful antigenic site responsible for eliciting both T- and B-cell immune response. The possible application of this specific epitope in vaccine development or AIDS diagnosis is discussed.

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.

Epitope Mapping of HIV1 gp41 Protein for Korean Anti - HIV1 Antisera using Synthetic Peptides / 대한면역학회지

The N-terminal sequence of HIV1 gp41 (amino acid residues 584-623) was known to be the immundominant region of HIV1 gp41 protein. In order to determine epitope for gp41 protein of Korean anti-HIV1 positive sera, multiple antigenic peptides (MAPs) for the sequences corresponding to 584-604, 590-612, 604-623 and 584-618 of HIV1 gp41 were synthesized by solid phase method using Fmoc-Lys (Fmoc)-OH and used as coating antigens for ELISA. The reactivities of the synthetic peptides with Korean HIV1 positive (21 samples) and anti-HIV1 negative sera (22 samples) obtained from healthy blood doner were estimated by an indirect ELISA. MAPs for 584-604, 590-612 and 604-623 of gp41 reacted with 62 %, 100 % and 81 % of Korean anti-HIV1 positive sera tested, respectively. The results suggest that the epitope for HIV1 gp 41 for Korean anti-HIV1 positive sera is located in the region of amino acid 590-612 of gp41. MAP for gp41 (584-618) reacted with all (100 %) of anti-HIV1 positive sera tested, but did not react with anti-HlV1 negative sera. In addition, this MAP reacted stronger with seven samples of anti-HIV1 positive sera of anti-HIV1/2 combo performance panel than the mixture of 584-604, 590-612 and 604-623 of gp41, but did not react with anti-HIV negative serum. The high sensitivity and selectivity of MAP of gp41 (584-618) suggest that this peptide as a coating antigen in an ELISA system will be useful for antibody detection of HIV1.

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.

Production and characterization of HPV16 recombinant capsid protein L2 in E.coli

No abstract available.

Identification and partial purification of pollen allergens from Artemisia princeps

The pollen of Artemisia has been considered as the main late summer-autumn allergen source in this country. To identify its allergenic components, Artemisia princeps pollen extracts were separated by 10% sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE), and transferred to nitrocellulose membrane, where IgE binding components were detected by the reaction with sera of twenty Artemisia-allergic patients and 125I-anti-human IgE, sixteen components in the molecular range of 10,000 and 85,000 daltons were detected. Twelve bands bound to IgE from 50% of the sera tested, and two bands (37,000, 23,000 daltons) showed the highest (85%) frequency of IgE-binding in twenty sera tested. When the gel of SDS-PAGE with Artemisia pollen extracts was sliced into 11 allergenic groups (AG) and the protein of each AG was obtained by the gel elution method, the wormwool-RAST inhibition test showed that the AG 10 demonstrated to be the most potent, and the AG 7 was the next. Six AGs showed significant responses (more than 100% of wheal size to histamine, 1 mg/ml) on the skin prick test in more than 50% of the patients tested. It is suggested that electrophoretic transfer analysis with SDS-PAGE may be a valuable method for Artemisia allergen identification, and the possibility of partial purification of allergens by employing gel elution is discussed.

Identification and partial purification of pollen allergens from Artemisia princeps

The pollen of Artemisia has been considered as the main late summer-autumn allergen source in this country. To identify its allergenic components, Artemisia princeps pollen extracts were separated by 10% sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE), and transferred to nitrocellulose membrane, where IgE binding components were detected by the reaction with sera of twenty Artemisia-allergic patients and 125I-anti-human IgE, sixteen components in the molecular range of 10,000 and 85,000 daltons were detected. Twelve bands bound to IgE from 50% of the sera tested, and two bands (37,000, 23,000 daltons) showed the highest (85%) frequency of IgE-binding in twenty sera tested. When the gel of SDS-PAGE with Artemisia pollen extracts was sliced into 11 allergenic groups (AG) and the protein of each AG was obtained by the gel elution method, the wormwool-RAST inhibition test showed that the AG 10 demonstrated to be the most potent, and the AG 7 was the next. Six AGs showed significant responses (more than 100% of wheal size to histamine, 1 mg/ml) on the skin prick test in more than 50% of the patients tested. It is suggested that electrophoretic transfer analysis with SDS-PAGE may be a valuable method for Artemisia allergen identification, and the possibility of partial purification of allergens by employing gel elution is discussed.

Characterization of Tumor Specific Antigens on the Plasma Membrane Surface of Rat Hepatomas lnduced by 3'-Me DAB and ldentification of the Common Tumor Specific Antigens from Rat Hepatomas lnduced by Different Chemical Hepatocarcinogens

Three different chemical carcinogens, 2-acetylaminofluorene (AAF), diethylnitrosamine(DENA), and 3'-methyl-4dimethylaminoazobenzene (3'-Me DAB) were used to induce hepatomas in rats. Plasma membrane surface proteins of normal rat liver cells and rat hepatomas were extracted with 3M KCI. From the analysis of the proteins of normal rat liver and rat hepatoma induced by 3'-Me DAB by discontinuous polyacrylamide gel electrophoresis(Disc-PAGE), under nonreducing and nondenaturing conditions polyacrylamide gel electrophoresis in the presence of SDS and 2-mercaptoethanol (SDS-PAGE), Sephadex G-200 gel permeation chromatography, DEAE-A50 ion-exchange chromatography and two-dimensional gel electrophoresis, at least three tumor specific antigens were identified. One had a molecular weigh of 66,000 (pl=6.79) while the other two had the same molecular weight 73,000 but differed in their isoelectric points (7.58 and 7.81). For immunological analysis of tumor specific antigens, the absorbed antiserum was prepared. Plasma membrane surface proteins of rat hepatoma induced by 3'-Me DAB were used to obtain New Zealand White male rabbit antiserum. Rabbit antiserum was then reacted with the proteins isolated from the plasma membrane surface of normal rat liver and the absorbed antiserum reacting specifically with the tumor specific antigens derived by 3'-Me DAB was obtained. Using the absorbed antiserum, the immunoreactivities of plasma membrane surface proteins isolated from rat hepatomas induced by 3'-Me DAB, AAF, and DENA were compared by Ouchterlony double immunodiffusion analysis and immunoelectrophoresis. To characterize the proteins reacting to the absorbed antiserum, immunoglobulin G was separated from the absorbed antiserum and coupled to cyanogen bromide-activated Sepharose CL-4B. The isolated proteins from the plasma membrane surface proteins of 3'-Me DAB-induced hepatoma using this immunoaffinity chromatography had molecular weights of 66,000 and 73,000. The localization of these proteins on surface plasma membranes of rat hepatomas induced by 3'-Me DAB was confirmed by an immunofluorescence technique. The experimental results revealed the existence of cross-reacting common antigens on the plasma membrane surface of rat hepatomas induced by different hepatocarcinogens.

Effects of Calcium Channel Blockers and Insulin on the Platelet Function in Patients with Diabetes Mellitus

Platelet aggregability was compared between platelets isolated from normal subjects and patients with diabetes mellitus in order to evaluate the effects of calcium channel blockers and insulin on the platelet function. The threshold aggregating concentration of adenosine diphosphate (ADP), which induces the second phase aggregation and reflects the platelet release reaction, was found to be significantly lower in diabetics than in normal subjects (1.8 microM vs 7.5 microM ). It was observed that the second phase aggregation curve induced by ADP was inhibited by in vitro treatment of platelets with insulin (10-100 microU/ml), verapamil (1-10 microM ), and diltiazem (1 microM) in diabetics. The result also shows that the inhibition was enhanced when insulin and calcium channel blockers were used together for in vitro treatment of diabetic platelets. Thus, the present study suggests that the use of calcium channel blockers combined with insulin would be more effective than the use of insulin alone in the prevention of diabetic vascular disease.

A Simplified Colorimetric Assay of Nonenzymatic Glycosylation of Human low Density Lipoproteins in Normal and Diabetes Mellitus

A simplified colorimetric method for measurement of the levels of glycosylation of proteins was developed by a modification of an existing method. Employing this method, the extent of nonenzymatic glycosylation of apolipoprotein B subspecies(B-100, B-74, B-26), LDL, VLDL and total serum proteins in human plasma obtained from patients with diabetes mellitus and control subjects was compared. Plasma LDL (1.019 < d < 1.063) and VLDL(d < 1.006) were separated using the sequential ultracentrifugation method, and the subspecies of apolipoprotein B were isolated by extracting them from polyacrylamide gels after they were separated by preparative SDS-polyacrylamide gel electrophoresis. Increases in the level of glycosylation of serum proteins, LDL, VLDL, and apo B subspecies obtained from diabetic patients were observed. Among them, the increases of glycosylated LDL and apo B-26 were most significant (p < .001). Also, good correlations were found between glycosylations of apo B-26 and LDL (r=.88), and glycosylation of LDL and LDL cholesterol level(r=.79). The results also showed an excellent correlation between levels of HbA1c and glycosylated apo B-26(r=.93).