Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q8NB91 (FAB)
 3,573 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fruit bromelain FA2, the main proteinase component of the juice of pineapple fruit, has been purified and characterized. 1. Efficient extraction of this enzyme from the crude material was possible using "Cellulosin AP," a microbial polysaccharidase preparation containing cellulase, hemicellulase, and pectinase. The enzyme was purified mainly by successive applications of anion-exchange chromatography, yielding an apparently homogeneous protein as judged by several physical, chemical, and immunochemical criteria. Properties of FA2 include: molecular weight, 31,000; isoelectric point, pH 4.6; absorbance at 280 nm of a 1% solution at pH 7.0 per cm, 19.2. 2. FA2 gave only alanine phenylthiohydantoin upon amino-terminal group analysis by the Edman procedure. Stepwise degradation yielded the amino-terminal sequence Ala-Val-Pro-Gln-Ser-Ile-Asp-Trp-Arg-Asp-Tyr-Gly-Ala. The amino acid composition of FA2 was not markedly different from that of stem bromelain, except for a much smaller lysine content and a smaller alanine content relative to glycine in FA2. FA2 contained neither amino sugars nor neutral carbohydrates as determined by several methods, so FA2 is not a glycoprotein. 3. By labeling the reactive cysteine residue (CYS) with [14C]iodoacetate, the following partial amino acid sequence has been determined. Asn-Glx-Asn-Pro-Cys-Gly-Ala-CYS.
 ...
PMID:Purification and characterization of a proteinase from pineapple fruit, fruit bromelain FA2. 95 52

The solid-phase synthesis of the N alpha-Fmoc analog of protein kinase C substrate (PKCS, Lys-Arg-Ala-Lys-Ala-Lys-Thr-Thr-Lys-Lys-Arg) was characterized by low recovery from the resin and the concomitant appearance of four impurities. FAB-MS revealed molecular weights for two of these impurities that corresponded to the desired peptide plus Tos or Bzl. The other two were justified by invoking a CO2 elimination of the Clz protecting group to yield: 1) peptide plus 2-chlorobenzyl (ClBzl) and 2) peptide plus ClBzl and Tos. A CF-FAB analysis of carboxypeptidase digestions allowed observation of peptide cleavage down to an ion corresponding to lysine, Fmoc, and the corresponding protecting group(s). These data revealed that the impurities were not the result of incomplete deprotection but the result of migration of the protecting groups to the N-terminal end of the peptide. NMR experiments were subsequently performed and revealed the exact site of substitution: the meta positions of the N-terminal Fmoc. These impurities are presumed to arise by electrophilic aromatic substitution of the fluorene group during HF treatment. The desired Fmoc analog served as a convenient, albeit low-yielding, intermediate for purification of the highly charged PKCS by preparative self-displacement HPLC.
 ...
PMID:Hydrogen fluoride catalyzed migration of side chain protecting groups onto Fmoc during solid phase peptide synthesis. Characterization by CF-FAB analysis of carboxypeptidase digestions and NMR spectroscopy. 128 38

Peptides of the FXRFamide family, where X = M, I or L, are broadly distributed among invertebrates. Two such peptides were purified and sequenced from the free-living nematode, Panagrellus redivivus. Immunohistochemical techniques localized FMRFamide-like material in several regions of these organisms, including the nerve cords and, most prominently, in paired groups of cells located caudally to the base of the pharynx. RIA determinations gave an estimate of 2.8 nmol immunoreactive peptide/g of an acetone extract of P. redivivus. Four sequential HPLC purification steps, followed by sequencing by automated Edman degradation and FAB-MS, led to the identification of Ser-Asp-Pro-Asn-Phe-Leu-Arg-Phe-amide (SDPNFLRFamide) and Ser-Ala-Asp-Pro-Asn-Phe-Leu-Arg-Phe-amide (SADPNFLRFamide) as members of the FXRFamide family in this nematode.
 ...
PMID:Two FMRFamide-like peptides from the free-living nematode Panagrellus redivivus. 140 99

1. Polyacrylamide gel electrophoresis in ultra-narrow immobilized pH gradient shifted the "Hb fast" band of AA buffalo phenotype haemoglobin into two components which were named Hb1 and Hb3. 2. Urea/Triton electrophoresis and reversed-phase HPLC demonstrated that Hb1 and Hb3 differ in the presence of two structurally distinct alpha chains (alpha 1 and alpha 3), also suggesting that the alpha chains must differ for neutral amino acid substitution. 3. Extensive mass spectrometric analysis on several digests (FAB overlapping) meant to determine the complete sequence of the constituent chains. 4. Two amino acid replacements (Lys 18----His and Asn 116----His) were present in the beta chain with respect to the bovine (A phenotype) chain, whereas the alpha 1 and alpha 3 globins were found to contain four amino acid replacements compared to the bovine alpha, three of which were identical (Glu 23----Asp, Glu 71----Gly and Phe 117----Cys) and, notably, an insertion of Ala at position 123-124. 5. Furthermore, alpha 1 contains Phe at position 130 whereas alpha 3 contains Ser at position 132 (following the modified numbering as a consequence of the Ala insertion).
 ...
PMID:River buffalo (Bubalus bubalis L.) AA phenotype haemoglobins: characterization by immobiline polyacrylamide gel electrophoresis and high performance liquid chromatography and determination of the primary structure of the constitutive chains by mass spectrometry. 149 82

The primary structure of some new lipodepsipeptides named syringopeptins, produced by plant pathogenic strains of Pseudomonas syringae pv. syringae has been determined by a combination of chemical methods, 1H and 13C NMR spectroscopy and FAB mass spectrometry. Two syringomycin-producing strains afforded 3-hydroxydecanoyl-Dhb-Pro-Val-Val-Ala-Ala-Val-Val-Dhb-Ala-Val-Ala- Ala-Dhb-aThr-Ser-Ala-Dhb-Ala-Dab-Dab-Tyr, with Tyr acylating a Thr to form a macrolactone ring, and smaller amounts of the 3-hydroxydodecanoyl homologue. Evidence was obtained that a third syringomycin-producing strain and a syringotoxin-producing strain synthesize 3-hydroxydecanoyl-Dhb-Pro-Val-Ala-Ala-Val-Leu-Ala-Ala-Dhb-Val-Dhb- Ala-Val-Ala-Ala-Dhb-aThr-Ser-Ala-Val-Ala-Dab-Dab-Tyr, with Tyr and aThr forming again the macrolactone ring, and smaller amounts of the 3-hydroxydodecanoyl homologue.
 ...
PMID:Syringopeptins, new phytotoxic lipodepsipeptides of Pseudomonas syringae pv. syringae. 193 37

Aureobasidin A, a new antifungal antibiotic, was isolated from the culture medium of Aureobasidium pullulans R106. Aureobasidin A was a cyclic depsipeptide consisting of eight alpha-amino acid units and one hydroxy acid unit. The structures of the units were found by acid hydrolysis of the antibiotic to be 2(R)-hydroxy-3(R)-methylpentanoic acid, beta-hydroxy-N-methyl-L-valine, N-methyl-L-valine, L-proline, allo-L-isoleucine, N-methyl-L-phenylalanine, L-leucine, and L-phenyl-alanine. The sequence of the units was identified by NMR and FAB-MS of the products from the alkaline hydrolysis of aureobasidin A.
 ...
PMID:Structure of aureobasidin A. 193 14

Eight sperm-activating peptides containing a novel amino acid were isolated from the egg jelly of the sea urchin Tripneustes gratilla. Accurate mass measurement of the peptide in FAB mass spectrometry showed that the mass of the novel amino acid residue was 224.978. On the basis of the isotopic ion distribution and the degree of unsaturation, the mass value indicated that the elemental composition of the amino acid residue was C9H8O1N1Br1, suggesting that the novel amino acid was bromophenylalanine. Proton NMR spectroscopy, amino acid analysis, and RP-HPLC with three synthetic isomers of bromophenylalanine demonstrated that o-bromophenylalanine was the novel amino acid. Derivatization of the amino acid with Marfey's reagent, (1-fluoro-2,4-dinitrophen-5-yl)-L-alanine amide (FDAA), further indicated that the amino acid was the L-isomer. In other sperm-activating peptides isolated from the egg jelly of the sea urchin, both m- and p-bromophenylalanines were discovered. The presence of m-bromophenylalanine has not been previously reported in natural products, while p-bromophenylalanine is found in theonellamide F, an antifungal bicyclic peptide from a marine sponge.
 ...
PMID:Identification of a novel amino acid, o-bromo-L-phenylalanine, in egg-associated peptides that activate spermatozoa. 205 27

Pyoverdins were isolated and characterized respectively from the cultures of Pseudomonas tolaasii NCPPB 2192 (pyoverdins Pt, Pt A, and Pt B) and Pseudomonas fluorescens CCM 2798 (Pyoverdins Pf/1, Pf/2, Pf, Pf/3/1, and Pf/3/2) each grown in iron-deficient conditions. Their structures were established by using FAB-MS, NMR, and CD techniques. These siderophores are chromopeptides, and all but one (pyoverdin Pf/3/3) possess at the N-terminal end of their peptide chain the same chromophore that has been reported in pyoverdin Pa from Pseudomonas aeruginosa ATCC 15692 [Wendenbaum, S., Demange, P., Dell, A., Meyer, J. M., & Abdallah, M. A. (1983) Tetrahedron Lett. 24, 4877-4880] and pseudobactin B 10 from Pseudomonas B10 [Teintze, M., Hossain, M. B., Barnes, C. L., Leong, J., & Van der Helm, D. (1981) Biochemistry 20, 6446-6457] which is derived from 2,3-diamino-6,7-dihydroxyquinoline. In pyoverdins Pt this chromophore is bound to a linear peptide chain D-Ser-L-Lys-L-Ser-D-Ser-L-Thr-D-Ser-L-OHOrn-L-Thr-D-Ser-D-OHOrn (cyclic) which has its C-terminal end blocked by cyclic D-N delta-hydroxyornithine. In pyoverdins Pf, the peptide chain is also linear, SerCTHPMD-Gly-L-Ser-D-threo-OHAsp-L-Ala-Gly-D-Ala-Gly-L-O HOrn(cyclic), and contains an unusual natural amino acid which is the result of the condensation of 1 mol of serine and 1 mol of 2,4-diaminobutyric acid, forming a cyclic amidine. The pyoverdins Pt differ only in substituent bound to the nitrogen on C-3 of the chromophore, which is succinic acid in pyoverdin Pt A, succinamide in pyoverdin Pt, and alpha-ketoglutaric acid bound to the chromophore by its C-5 carbon atom in pyoverdin Pt B. Similarly, pyoverdin Pf/1, pyoverdin Pf/2, pyoverdin Pf (the major compound), and pyoverdin Pf/3/2 are substituted respectively by L-malic acid, succinic acid, L-malic amide, and succinamide. Pyoverdin Pf/3/3 has the same chromophore as azotobactin, the peptidic siderophore of Azotobacter vinelandii. These pyoverdins are very similar to pseudobactin B 10, the siderophore of Pseudomonas B10: they are linear peptides containing three bidentate groups strongly chelating Fe(III) and blocked at their N-terminal end by the catecholic chromophore and at their C-terminal end by cyclic N delta-hydroxyornithine. They differ therefore from other pyoverdins such as those from P. aeruginosa ATCC 15692 which contain a partly cyclic peptide [Briskot, G., Taraz, K., & Budzikiewicz, H. (1989) Liebigs Ann. Chem., 375-384].
 ...
PMID:Bacterial siderophores: structures of pyoverdins Pt, siderophores of Pseudomonas tolaasii NCPPB 2192, and pyoverdins Pf, siderophores of Pseudomonas fluorescens CCM 2798. Identification of an unusual natural amino acid. 212 1

A strain of the filamentous cyanobacterium Nostoc sp. isolated from a lake in Finland was found to produce at least nine hepatotoxic peptides with chemical and toxicological properties similar to those of the hepatotoxic hepta- and pentapeptides produced by other cyanobacteria. Toxins were isolated and purified by high-performance liquid chromatography. Amounts available for five of the purified toxins (P6, P14, P15, P16, and P18) were adequate for high-performance liquid chromatography amino acid analysis and determination of molecular weight by fast-atom bombardment-mass spectrometry (FAB-MS). Quantities of three toxins (P14, P15, and P16) were adequate for further analysis by high-resolution FAB-MS, FAB-MS/MS, and 1H-nuclear magnetic resonance. Analysis showed that the toxins are new types of microcystin-LR homologs. Microcystin-LR contains equimolar amounts of D-alanine, L-leucine, D-erythro-beta-methylaspartic acid, L-arginine, ADDA (3-amino-9-methoxy-2,6,8-trimethyl-10-phenyl-4,6-decadienoic acid), D-glutamic acid, and N-methyldehydroalanine (molecular weight [MW], 994). Nostoc sp. strain 152 was found to produce the following microcystin-LR homologs: (i) P6 contains an extra methylene group most probably due to the presence of N-methyldehydrobutyrine instead of N-methyldehydroalanine (MW, 1,008); (ii) P14 is O-acetyl-O-demethyl ADDA-microcystin-LR (MW, 1,022); (iii) P15 is 3-demethyl-O-acetylADDA-homoarginine-microcystin-LR (MW, 1,036); (iv) P16 is 3-demethyl-O-acetyl-O-demethylADDA-microcystin-LR (MW, 1,008); (v) P18 is 3-demethyl-O-acetyl-O-demethylADDA-homoarginine-microcystin- LR (MW, 1,022). The toxicities of the new microcystin homologs were not significantly different from those of microcystin-LR or demethylmicrocystin-LR.
 ...
PMID:Isolation and characterization of hepatotoxic microcystin homologs from the filamentous freshwater cyanobacterium Nostoc sp. strain 152. 212 13

We have constructed a new screening system for detecting microbial products that enhance host resistance against bacterial infection. It was found that a new compound with such activity is produced by a soil isolate classified as Nocardia sp. SANK 60484. The compound was isolated from the culture filtrate of the organism and named aladapcin after its amino acid composition. Aladapcin was obtained as an amphoteric white amorphous powder with the molecular formula, C13H25N5O5. It consists of 2 mol of D-alanine and 1 mol of meso-diaminopimelic acid. From the analysis of IR, 1H NMR and FAB-MS spectra, the structure was assigned to be a tripeptide. Aladapcin enhanced host resistance against an experimental Escherichia coli infection in mice at doses ranging between 1 and 100 micrograms/kg.
 ...
PMID:Aladapcin, a new microbial metabolite that enhances host resistance against bacterial infection. Production, isolation, physico-chemical properties and biological activities. 219 20


1 2 3 4 Next >>