scholarly journals Arg-27, Arg-127 and Arg-155 in the β-trefoil protein barley α-amylase/subtilisin inhibitor are interface residues in the complex with barley α-amylase 2

1995 ◽  
Vol 309 (3) ◽  
pp. 969-976 ◽  
Author(s):  
K W Rodenburg ◽  
E Várallyay ◽  
I Svendsen ◽  
B Svensson
Keyword(s):  
Monoclonal Antibody ◽  
Interleukin 1 ◽  
Alpha Amylase ◽  
Reverse Phase Hplc ◽  
Reverse Phase ◽  
Multiple Contacts ◽  
Arginine Residues ◽  
Arginine Modification ◽  
Subtilisin Inhibitor ◽  
Sensitive Group

Arginine residues in barley alpha-amylase/subtilisin inhibitor (BASI) involved in binding to barely alpha-amylase 2 (AMY2) were differentially labelled using AMY2 as protectant and phenylglyoxal (PGO) and [14C]PGO as modifying agents. Chymotryptic fragments of labelled BASI were purified by reverse-phase HPLC, and we concluded that the radiolabelled Arg-27, Arg-155 and most likely Arg-127, identified by amino acid, sequence and 14C analyses, are protected by AMY2. While Arg-106 and Arg-107 showed intermediate reactivity and apparently were only partly accessible, Arg-15, Arg-41 and Arg-61 reacted with PGO and were thus exposed in the BASI-AMY2 complex. Patterns of arginine modification by [14C]PGO in free or in AMY2-complexed BASI were consistent with the results of differential labelling. The AMY2-protected arginines in BASI are at a distance from each other, as deduced from crystal structures of different beta-trefoil proteins (Erythrina caffra and soybean trypsin inhibitors, interleukin-1 alpha and -1 beta and WASI, the wheat homologue), suggesting that the BASI-AMY2 complex has multiple contacts at a larger interface. Accordingly, 11-16-residue-long BASI oligopeptides synthesized to include Arg-27, Arg-106/Arg-107 or Arg-127 were unable to suppress the formation of BASI-AMY2 or the effect of an inhibitory monoclonal antibody to BASI. Since Arg-27 is not conserved in rice and wheat ASIs, we further propose that Arg-155 in BASI is the kinetically identified PGO-sensitive group that is essential for inhibition [Abe, Sidenius and Svensson (1993) Biochem. J. 293, 151-155].

scholarly journals Arginine is essential for the α-amylase inhibitory activity of the α-amylase/subtilisin inhibitor (BASI) from barley seeds

1993 ◽  
Vol 293 (1) ◽  
pp. 151-155 ◽  
Author(s):  
J Abe ◽  
U Sidenius ◽  
B Svensson
Keyword(s):  
Inhibitory Activity ◽  
Enzyme Inhibitor ◽  
Three Dimensional ◽  
Order Rate Constant ◽  
Alpha Amylase ◽  
Three Dimensional Model ◽  
Pseudo First Order Reaction ◽  
Arginine Residues ◽  
Subtilisin Inhibitor ◽  
Target Enzyme

Treatment of barley alpha-amylase/subtilisin inhibitor (BASI) with reagents specific for arginine, histidine, methionine and tyrosine residues and amino and carboxyl groups indicates that an arginine residue(s) is essential for its action on the target enzyme barley alpha-amylase 2. Phenylglyoxal modified eight out of 12 arginine residues in BASI. Kinetic analysis shows that the inactivation of BASI follows a pseudo-first-order reaction and is due to reaction with one molecule of phenylglyoxal; the second-order rate constant is determined to be 2.95 M-1.min-1. At pH 8.0, BASI and barley alpha-amylase 2 form an inactive 1:1 complex. The Ki value of this association is 2.2 x 10(-10) M. The alpha-amylase protects four arginine residues and also the alpha-amylase inhibitory activity of BASI against phenylglyoxal. When BASI from the phenylglyoxal-modified target enzyme-inhibitor complex is isolated and subjected to a second treatment with phenylglyoxal, four additional arginine residues are modified, with concomitant loss of the inhibitory activity. These results are discussed in relation to a three-dimensional model of BASI based on the known structure of the corresponding inhibitor from wheat.

scholarly journals Purification to homogeneity and amino acid sequence analysis of two anionic species of human interleukin 1.

1986 ◽  
Vol 164 (1) ◽  
pp. 237-250 ◽  
Author(s):  
P M Cameron ◽  
G A Limjuco ◽  
J Chin ◽  
L Silberstein ◽  
J A Schmidt
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Interleukin 1 ◽  
Amino Acid Residues ◽  
Amino Acid Sequence Analysis ◽  
Reverse Phase Hplc ◽  
Reverse Phase ◽  
Molecular Weights ◽  
Maximal Stimulation ◽  
Anionic Species

Two anionic species of human IL-1 have been purified to homogeneity. These molecules were characterized as having pI of 5.4 and 5.2 and molecular weights identical to IL-1/6.8 (17,500). The specific activities of IL-1/5.4 and IL-1/5.2, as measured in the mouse thymocyte co-mitogenic assay, were identical to that of IL-1/6.8, namely 1.2 X 10(7) U/mg, with half-maximal stimulation observed at 2 X 10(-11) M. IL-1/5.4 and IL-1/5.2 were found to be antigenically distinct from IL-1/6.8 in an ELISA. IL-1/5.4 was structurally distinct from IL-1/6.8 based on reverse-phase HPLC or CNBr peptides. Intact IL-1/5.2 and three intact CNBr peptides of IL-1/5.4 were sequenced, with the identification of 74 amino acid residues. These sequences were found to correspond exactly with the amino acid sequence deduced from the IL-1-alpha cDNA reported by March et al.

Understanding Process Variables and their Interactions for Maximizing Production of Artemisinin Derivative Artemether (Anti-Malarial Drug) Through Cunninghamella echinulata var elegans at 5 L Bioreactor Level

2019 ◽  
Vol 15 (4) ◽  
pp. 442-452
Author(s):  
Kashyap Kumar Dubey ◽  
Punit Kumar
Keyword(s):  
Experimental Finding ◽  
Culture Broth ◽  
Quadratic Model ◽  
Optimum Conditions ◽  
Reverse Phase Hplc ◽  
Polar Solvents ◽  
Reverse Phase ◽  
Experimental Conditions ◽  
Cunninghamella Echinulata ◽  
Life Threatening

Background: Malaria is one of the life threatening diseases which is caused by Plasmodium sp. of protozoa and uses Anopheles mosquitos as vector. Plasmodium vivax and Plasmodium falciparum are common form of malaria parasite. Artemisinin is reported for its antimalarial activities and Artemether which is a methyl ether derivative of Artemisinin, has been found effective against P. falciparum. Methods: In the present study, bioconversion of Artemisinin into Artemether was carried out experimentally and the statistical tools like experimental factorial design and Response Surface Methodology were used to find optimal conditions (concentration of Artemisinin, age of inoculum, temperature & pH) using Cunninghamella echinulata var. elegans. Experimental conditions for maximum product recovery from culture broth were also optimized using various polar and non-polar solvents for extraction. Artemether purity was analyzed by reverse-phase HPLC. Experimental data was fitted in a quadratic model and effect of various parameters was analyzed. Results: It was found that bioconversion of Artemisinin into Artemether is growth associated process. It was observed that molasses used as carbon source supported production of Artemether to 3.4g/L. The biomass and oxygen are key element affecting of bioconversion of Artemisinin into Artemether such as higher dissolved oxygen reduced the Artemether bioconversion. The highest bioconversion of Artemisinin into Artemether was obtained at temperature 25.5oC, 5g/L concentration of Artemisinin, at age of inoculum of 44.5 h and at pH 6.0. Model suggested the highest bioconversion of Artemisinin into Artemether was 54% at shake flask level which was near about experimental finding. An optimal condition for bioconversion was also analyzed and 64% bioconversion was obtained in 5L bioreactor. Conclusion: The outcomes of the study provided optimum conditions for bioconversion of Artemisinin into Artemether.

scholarly journals Orphan Designation and Cisplatin/Hyaluronan Complex in an Intracavitary Film for Malignant Mesothelioma

Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 362
Author(s):  
Sabrina Banella ◽  
Eride Quarta ◽  
Paolo Colombo ◽  
Fabio Sonvico ◽  
Antonella Pagnoni ◽  
...  
Keyword(s):  
Sodium Hyaluronate ◽  
Chloride Ions ◽  
Complete Resection ◽  
Size Exclusion ◽  
European Medicines Agency ◽  
Reverse Phase Hplc ◽  
Reverse Phase ◽  
Pharmaceutical Development ◽  
Film Forming ◽  
Exclusion Chromatography

Pleural mesothelioma is a lung diffuse tumor, whose complete resection is unlikely. Consequently, metastases reappear where the primary tumor was removed. This paper illustrates the orphan medicine designation procedure of an intracavitary cisplatin film and related pharmaceutical development aspects requested by the European Medicines Agency (EMA) in its Scientific Advice. Since cisplatin pharmacokinetics from the implanted film in sheep resulted substantially modified compared to intravenous administration, the formation of a cisplatin/hyaluronan complex had been hypothesized. Here, the interaction between sodium hyaluronate (NaHA) and cisplatin (CisPt) was demonstrated. Size exclusion chromatography qualitatively evidenced the complex in the film-forming mixture, only showing the NaHA peak. Atomic absorption spectroscopy of the corresponding fraction revealed platinum, confirming the interaction. Reverse phase HPLC quantified about 5% free cisplatin in the film-forming mixture, indirectly meaning that 95% was complexed. Finally, a study of CisPt release from the film assessed how CisPt/NaHA complex affected drug availability. In water, a medium without chloride ions, there was no release and the film remained intact for 48 h and longer, whereas the placebo film dissolved in 15 min. In 0.9% NaCl medium, the film became more soluble, dissolving within 3–4 h. However, cisplatin release was still controlled by the existing complex in solution until chloride ions displaced it. While the film modified its dissolution with aging, CisPt release remained unaffected (90% released in 48 h).

Quantitation of Amiodarone and Desethylamiodarone from Blood Serum and Myocardium Using Reverse Phase HPLC

1987 ◽  
Vol 10 (12) ◽  
pp. 2625-2637 ◽  
Author(s):  
J. Alan Menius ◽  
D. James Schumacher ◽  
Emily A. Hull-ryde ◽  
Cyril Y. Leung ◽  
Robin G. Cummings ◽  
...  
Keyword(s):  
Blood Serum ◽  
Reverse Phase Hplc ◽  
Reverse Phase

In vitro 19-norandrogen synthesis by equine placenta requires the participation of aromatase

1995 ◽  
Vol 144 (3) ◽  
pp. 517-525 ◽  
Author(s):  
S Moslemi ◽  
P Silberzahn ◽  
J-L Gaillard
Keyword(s):  
Silica Gel ◽  
Aromatase Inhibitors ◽  
Column Chromatography ◽  
Microsomal Fraction ◽  
Specific Activity ◽  
Reverse Phase Hplc ◽  
Reverse Phase ◽  
Term Placenta ◽  
Flow Detector

Abstract Explants of equine full-term placenta have been shown to synthesize 19-norandrogens from labelled androgens. Steroid metabolites were purified by silica-gel column chromatography then analysed and quantified by C18-reverse-phase HPLC coupled to a radioactive flow detector. 19-Norandrostenedione was subsequently recrystallized to constant specific activity, providing unequivocal evidence of its synthesis by the equine placenta. 19-Norandrostenedione synthesis appeared to be localized in the microsomal fraction. Regardless of the substrate used, formation of 19-norandrogens was far weaker than that of oestrogens; moreover, the yield of 17-oxosteroids produced was much greater than that of 17β-hydroxysteroids, suggesting the presence of a dehydrogenase with predominant oxidative activity. Sulphoconjugated steroids formed were less than 0·5% of total steroids. Although 19-nortestosterone could not be generated by equine purified aromatase incubated with labelled testosterone, the synthesis of 19-norandrogens and oestrogens by equine placental explants was blocked by two specific aromatase inhibitors, 4-hydroxyandrostenedione and fadrozole. Our results provide evidence for a placental origin of at least a part of the 19-norandrogens previously identified in the blood of the pregnant mare. Furthermore, it is suggested that 19-norandrogen biosynthesis would involve the enzymatic metabolism of 19-oxygenated androgens formed by equine aromatase. Journal of Endocrinology (1995) 144, 517–525

scholarly journals RP-HPLC Determination of Raloxifene in Pharmaceuticl Tablets

2006 ◽  
Vol 3 (1) ◽  
pp. 60-64 ◽  
Author(s):  
P. Venkata Reddy ◽  
B. Sudha Rani ◽  
G. Srinu Babu ◽  
J. V. L. N. Seshagiri Rao
Keyword(s):  
Flow Rate ◽  
Retention Time ◽  
Mobile Phase ◽  
Dosage Forms ◽  
Hplc Method ◽  
Reverse Phase Hplc ◽  
Reverse Phase ◽  
Pharmaceutical Dosage Forms ◽  
Rp Hplc

A reverse phase HPLC method is developed for the determination of Raloxifene in pharmaceutical dosage forms. Chromatography was carried out on an inertsil C18 column using a mixture of acetonitrile and phosphate buffer (30:70 v/v) as the mobile phase at a flow rate of 1 mL/min. Detection was carried out at 290 nm .The retention time of the drug was 10.609 min. The method produced linear responses in the concentration range of 0.5-200 µg/mL of Raloxifene. The method was found to be applicable for determination of the drug in tablets.

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