Thin-layer chromatography of 1-dimethylaminonaphthalene-5-sulphonyl derivatives of amino acids present in superfutases of cat cerebral cortex

1. Five new solvent systems are reported for the separation of 1-dimethylaminonaphthalene-5-sulphonylamino acids by thin-layer chromatography on silica gel. After two-dimensional chromatography with a suitable pair of these solvent systems, most of the 1-dimethylaminonaphthalene-5-sulphonyl derivatives were completely separated and could be located by their intense yellow fluorescence when viewed under u.v. light. 2. These techniques have been used to identify 21 amino acids present in superfusates of cat cerebral cortex, plasma and cerebrospinal fluid. 3. A method for the semiquantitative estimation of amino acids in biological fluids is described in which the fluorescent intensity of their separated 1-dimethylaminonaphthalene-5-sulphonyl derivatives was measured.     

Covalent bonding of protein to polyamine in the cyst coat of the protozoan Colpoda steinii

1. High-voltage electrophoresis and chromatography before and after reaction with 5-dimethylaminonaphthalene-1-sulphonyl chloride have identified putrescine and spermidine in hydrolysates of cyst coat proteins from the protozoan Colpoda steinii. 2. Amounts present varied with putrescine up to 19.7 and spermidine up to 16.9 residues per 1000 amino acid residues. 3. The amines were not, in the main, removed by acid or alkaline extraction or by reprecipitation. They were present in hydrolysates of peptides isolated electrophoretically from acid-degraded coat protein. 4. Proteolysis of oxidised coat protein produced a soluble core polypeptide to which the major proportion of the amines were attached and which had a simple composition. It was composed almost entirely of glutamic acid or glutamine, glycine, serine and cysteic acid, these residues being present in the approximate ratio of 10:2:1:1. 5. When coat protein was treated with 5-dimethylaminonaphthalene-1-sulphonyl chloride and hydrolysed no fully substituted amines could be detected but putrescine with one group substituted and spermidine derivatives with one and two groups substituted were present.     

Determination of 5-dimethylaminonaphthalene-1-sulfonyl derivatives of urinary polyamines by ion-pair high-performance liquid chromatography

A sensitive and specific method for the determination of diamines and polyamines by ion-pair high-performance liquid chromatography is described. The 5-dimethylaminonaphthalene-1-sulfonyl derivatives of putrescine, 1,6-diaminohexane, spermidine and spermine are separated on a μBondapak C₁₅ reversed-phase column with 1-heptanesulfonic acid and acetonitrile as the mobile phase. All compounds are eluted within 30 min using a programmed solvent gradient system. The method has a lower detection limit of 1 pmole on column.Because of the simplicity of the method, its application provides a better means for closely monitoring patients undergoing treatment for various types of genito-urinary neoplastic diseases.     

Interaction of synthetic N-5-dimethylaminonaphthalene-1-sulfonyl-apolipoprotein C-II peptides with lipoprotein lipase

Synthetic fragments of apo-C-II, specifically labeled on their NH2-terminals with the 5-dimethylaminonaphthalene-1-sulfonyl (dansyl or DNS) fluorophore, have been prepared by solid phase peptide synthesis. When a complex is formed between bovine milk lipoprotein lipase and N-dansyl-apo-C-II peptides, resonance energy transfer occurs from the tryptophan residues of the enzyme to the dansyl-labeled peptides upon excitation at 280 nm. In the absence of lipid, the association constant increases 10-fold when the length of the DNS peptide is increased from apo-C-II-DNS(64-78) (0.04 X 10(6) M-1) to apo-C-II-DNS(60-78) (0.3 X 10(6) M-1). In the presence of lipid, the association constants are dependent on peptide chain length, and increase from 0.4 X 10(6) M-1 for apo-C-II-DNS(64-78) to 2.2 X 10(7) M-1 for apo-C-II-DNS(43-78). The interactions are specific for lipoprotein lipase, are disrupted by guanidinium chloride, are not affected by 1.0 M NaCl, and are competitive with the corresponding nondansylated peptide. Apolipoproteins C-III and A-I, at 5 to 1 molar ratios, had no effect on the interaction. These findings demonstrate the importance of the COOH-terminal region in the lipoprotein lipase-apo-C-II interaction and show that activation of the enzyme involves a specific protein-protein interaction.     

Fluorescence technique for comparative studies of substrate-binding subsites in serine proteinases. Application to subtilisins.

A fluorescence technique for comparative studies of substrate-binding subsites in serine proteinases is described. It consists of: selective labelling of the corresponding subsites with a fluorescent group by using N alpha-dansyl(5-dimethylaminonaphthalene-1-sulphonyl)ated peptide chloromethanes containing different numbers of amino acid residues, and probing the immediate environment of the subsites by quenching experiments using ionic and neutral quenchers. Intramolecular distances between the subsites and particular chromophores can be also determined. The technique is of general applicability to all serine proteinases. The above mentioned approach was applied to two proteinases: subtilisin Novo and mesentericopeptidase. It was concluded that the substrate-binding site of mesentericopeptidase is considerably more polar than that of subtilisin Novo. Intramolecular distances between the labelled subsites and tryptophan residues in the two proteinases were determined.     

Fluorescent staining of L cell centromeres and chromocenters with 1-dimethylaminonaphthalene-5-sulfonyl chloride and G-bandings

Fluorescent staining patterns of L cell chromosomes with 1-dimethylaminonaphthalene-5-sulfonyl chloride (dansyl chloride) were studied. Ordinary air-dried L cell metaphase chromosomes exhibited relatively uniform and bright yellowish green fluorescence by dansyl-staining under the fluorescence microscope. However, after the chromosome preparations were treated with 10 mM NaCl for 24 h at 4 °C, which produced distinctive G-bands with Giemsa-staining, the centromeric regions and several interstitial regions of some particular chromosomes were clearly fluorescent but other regions showed only dull fluorescence. After the treatment of chromosome slides with cupric sulfite reagent, which converts sulfhydryls and disulfides to thiosulfates chromosomes showed clear G-bands which were indistinguishable from those after 10 mM NaCl treatment. By dansyl-staining, however, the cupric sulfite-treated chromosomes exhibited very faint fluorescence on their contour alone, and neither centromeric regions nor some interstitial regions of marker chromosomes had distinctly bright fluorescence.Although Giemsa-staining disclosed dark chromocenters in approx. 75% of interphase nuclei irrespective of pretreatments, dansyl-staining revealed bright chromocenters in approx. 60% of interphase nuclei in control slides, in about 40% of nuclei in 10 mM NaCl-treated slides, and in only about 30% of nuclei in cupric sulfite-treated preparations.These observations indicated that in the air-dried chromosome preparations, the distribution of protein over the metaphase chromosome is relatively uniform along its length, and that G-bands in the chromosome and Giemsa-staining of chromocenters in interphase nuclei are not significantly affected by apparent loss of protein from the preparations. It was also suggested that particular protein may be associated with the centromeric regions of L cell chromosomes. Some technical details of dansyl fluorochroming and the significance of the observations were discussed.     

Purification of blood carbonic anhydrases and specific detection of carbonic anhydrase isoenzymes on polyacrylamide gels with 5-dimethylaminonaphthalene-1-sulfonamide (DNSA).

Methods are presented for purification of carbonic anhydrases from guinea pig blood and specific visualization of carbonic anhydrase bands during and after electrophoresis using nondenaturing polyacrylamide gels. The carbonic anhydrases are detected on the gels as fluorescent complexes with 5-dimethylaminonaphthalene-1-sulfonamide in protein mixtures and in erythrocyte lysates that have been prechromatographed to remove hemoglobin.     

A new sensitive Edman-type reagent: 4-(N-1-dimethylaminonaphthalene-5-sulfonylamino)phenyl isothiocyanate. Its synthesis and application for micro-sequencing of polypeptides

A new fluorescent PITC homologue Edman-type reagent, 4-(N-1-dimethylaminonaphthalene-5-sulfonylamino)phenyl isothiocyanate (DNSAPITC), was synthesized following a simple three-step synthetic route. The reagent was crystallized and characterized by thin-layer chromatography, IR and electron impact mass spectrometry. Reference DNSAPTH-amino acid derivatives were prepared and a two-dimensional chromatography system on micro-polyamide sheets was developed for separating this mixture. On these sheets the sensitivity was 1-5 pmol, by exposure at 366 nm. Model peptides and proteins were subjected to Edman degradations with this new reagent. A similar coupling efficiency and repetitive degradation yield to those of PITC were found with this reagent. The advantages and limitations of this reagent for sensitive microsequencing are discussed.     

Determination of the naturally occurring monoacetyl derivatives of di- and polyamines

A method is described for the determination of pmol quantities of monoacetylputrescine, N¹-acetylspermidine, N⁸-acetylspermidine and related compounds. The method is based on the derivatization of these compounds with 5-dimethylaminonaphthalene-1-sulphonyl-chloride, followed by thin-layer chromatographic separation. Cleanup steps allow the application of the method to urine analyses. From the repeated determination of acetylated polyamines in the urine of healthy individuals it can be concluded that these conjugates are the major excretory form of di- and polyamines.The cleanup steps used in this procedure and the method described for the stabilization of 5-dimethylaminonaphthalene-1-sulphonyl derivatives on thin-layer plates are advantageous also for the analyses of total polyamines in urine hydrolysates, and in related applications of the dansylation method.     

Chemical, photochemical and spectroscopic characterization of an alkaline proteinase from Bacillus subtilis variant DY

Circular-dichroism and fluorescence studies indicate that the 5-dimethylaminonaphthalene-1-sulphonyl and phenylmethanesulphonyl derivatives of subtilisin DY have three-dimensional structure closely similar to that of native enzyme. The single tryptophan residue is largely accessible to the aqueous solvent, and is not directly involved in the enzyme-substrate interactions, since its photochemical modification causes only a partial inhibition of the enzyme activity. It appears very likely that the location of the single tryptophan residue in the three-dimensional structure of subtilisin DY is similar to that of the single tryptophan residue in subtilisin Carlsberg. Fluorescence-quenching experiments further indicate that the 14 tyrosine residues are also largely accessible to the aqueous solvent, and probably interact with hydrated peptide carbonyl groups. The charge environment for tryptophan and tyrosine residues in subtilisin DY, as deduced by quenching experiments with ionic species, is also discussed. In general, subtilisin DY displays strong similarities to subtilisin Carlsberg, as suggested by a comparative analysis of the amino acid composition and fluorescence properties.     

Intramolecular distances between tryptophan residues and the active-site serine residue in alkaline bacterial proteinases as measured by fluorescence energy-transfer studies.

Singlet-singlet energy transfer from the tryptophan residues to an active-site-serine-bound 5-dimethylaminonaphthalene-1-sulphonyl group was investigated in four subtilisins. The transfer distances for subtilisin Novo and mesentericopeptidase are 1.93 +/- 0.20 nm (19.3 +/- 2.0 A) and 1.81 +/- 0.20 nm (18.1 +/- 2.0 A) respectively. The positions of the indole groups in the three-dimensional structures of the two pairs of proteinases, namely subtilisin Novo and mesentericopeptidase on the one hand and subtilisins Carlsberg and DY on the other, are essentially identical.     

Positions in human serum albumin which involve the indole binding site. Sequence of 107-residue fragment.

The first 107 residues of Fragment C of human serum albumin have been sequenced and two positions at which affinity labels block the indole site determined. Histidine 23 is the position of blockage by bromoacetyl-L-tryptophan and lysine 67 is the position of blockage by 5-dimethylaminonaphthalene-1-sulfonyl chloride and probably pyridoxal-5'-phosphate. The presence of an indole ligand at the binding site markedly reduces incorporation of the label into the above lysyl residue, and in the case of 5-dimethylaminonaphthalene-1-sulfonyl chloride, increases incorporation into three other positions, lysine residues 13, 39, and 84. It is concluded that binding of the indole ligand on the site brings about conformational changes in the albumin structure exposing new reactive positions for 5-dimethylaminonaphthalene-1-sulfonyl chloride. There is a large accumulation of basic and hydrophobic residues and no glycine, serine, threonine, valine, aspartate, or cysteine residues in the sequence 10 to 43. Lysine 71 has been identified by amino acid analyses and sequence studies as the position acetylated by acetylsalicylic acid (Hawkins, D. R., Pinckard, N., Crawford, C. P., and Farr, R. S. J. Clin. Invest. (1969) 48, 536), establishing the structural relationships of two major ligand binding sites on albumin. The lone tryptophan is at position 86. Evidence indicates that within residues 1 to 86 of Fragment C and within residues of the A-Phe fragment (Mr equals approximately 10,000), the latter known to be adjacent to Fragment C in the whole albumin structure, exists the major binding sites of all ligands for human serum albumin.     

Change in aggregation state of insulin upon conjugation with 5-dimethylaminonaphthalene-1-sulfonyl group

Change in aggregation state of insulin upon conjugation with 5-dimethylaminonaphthalene-1-sulfonyl (DNS) group was investigated at neutral pH. DNS group was introduced exclusively into B1 phenylalanine, the N-terminus of the B-chain of insulin. The association state of insulin shifted toward a more highly aggregated one upon conjugation, depending on the mole fraction (d) of DNS group to insulin monomer; at d equal 0.3 the equilibrium between dimer and hexamer was dominant over the range of 1-600 microM, while at d equal 1.0-1.5 DNS-insulin formed a larger aggregate (dodecamer) which is stable over the range of 67-600 microM. The dissociation constant of dimer-hexamer equilibrium at d=0.3 was evaluated to be 2.5 x 10(-10) M2 from the fluorescence anisotropy of the DNS group, which was about one order of magnitude smaller than that of the dimer-hexamer equilibrium in native insulin. Spectroscopic data and fluorescence decay analyses indicated that there exist at least two different environments surrounding the dye bound to B1 phenylalanine and that they are both relatively hydrophilic. It is considered that the major part of DNS group has excitation and emission maxima at longer wavelength with relatively low quantum yield, while the minor part has excitation and emission maxima at shorter wavelengths with relatively high quantum yield. The fluorescence lifetime of the dye was modified by the change in quaternary structure of DNS-lifetime of the dye was modified by the change in quaternary structure of DNS-insulin. Remarkable depolarization of DNS fluorescence was observed at d equal 1.0 and d equal 1.5 due to energy transfer between DNS groups conjugated to B1 phenylalanine in the hexamer or the dodecamer. Critical transfer distance for inter-DNS energy transfer was evaluated to be 15 A. From the molecular model of the insulin crystal, this energy transfer is ascribed to the close proximity, within about 15 A, between DNS groups in dimer units of the hexamer or the dodecamer.     

Covalent attachment of fluorescent probes to the X-base of Escherichia coli phenylalanine transfer ribonucleic acid.

tRNA PheE, coli was labeled with the N-hydroxysuccinimide esters of 1-dimethylaminonaphthalene-5-sulfonyl glycine and N-methylanthranilic acid through reaction with the amino acid moiety of its X-base, whereby yields of 66% and 24%, respectively, were obtained. The purified dimethylaminonaphthalene-sulfonate derivative could not be aminoacylated and was found to be a strong competitive inhibitor of phenylalanine-tRNA synthetase [Ki=8X10(-7) M]. The N-methylanthraniloyl derivative could be charged to an extent of 5% as compared to native tRNA Phe. The fluorescence emission spectra of the derivatives are indicative of a slightly hydrophobic environment for both fluorophores. The results suggest that the integrity of the polar amino acid group of the X-base is required for the maintenance of the biologically active conformation.     

The binding of dansylated initiation factor 3 to the 30-S subunit of Escherichia coli: a fluorimetric and biochemical study

Initiation factor 3 (IF-3) has been labelled using dansyl (1-dimethylaminonaphthalene-5-sulphonyl) chloride under conditions designed to preserve the biological activity of the factor. The sites of modification of the IF-3 have been determined by peptide mapping and sequencing: about six lysines (73, 80, 91, 96, 99, 112) react in various proportions. However, if an IF-3 molecule bears more than one dansyl group on average then its activity is lost. The extent of incorporation is proportional to the amount of dansyl chloride used in the reaction. Spectrofluorimetric analysis of the dansyl-IF-3 leads to the following conclusions. (a) The motion of the dansyl label does not change greatly upon binding to the 30-S subunit. (b) The label is not close enough to any tryptophan group of the ribosome in the 30-S-subunit . IF-3 complex to allow energy transfer. (c) The IF-3 chain is folded so as to bring the tyrosine groups close to the dansyl-binding sites. (d) The stoichiometry of the binding of IF-3 to 30-S ribosomal subunits is close to 1:1 and the binding constant is 2 x 10(7) M-1. IF-3 also binds non-covalently the fluorescent indicator 8-anilinonaphthalene 1-sulphonate (ANS) with an apparent binding constant of approximately 8000 M-1. An interaction between ANS and poly(A-U-G), both bound to IF-3, was demonstrated. Combining these results with those for dansyl-IF-3 leads to a model for the interaction between IF-3 and the 30-S subunit involving a combination of 'hydrophobic' and electrostatic attraction between the factor and ribosomal RNA.     

Fluorescence lifetime and rotational correlation time of bovine serum albumin-sodium dodecyl sulfate complex labeled with 1-dimethylaminonaphthalene-5-sulfonyl chloride: Effect of disulfide bridges in the protein on these fluorescence parameters

A fluorescent dye, 1-dimethylaminonaphthalene-5-sulfonyl chloride, was used to label bovine serum albumin (BSA), intact and disulfide bridges-cleaved. The fluorescence lifetime and fluorescence anisotropy of the adducts in sodium dodecyl sulfate (SDS) solutions were studied by the nanosecond fluorescence depolarization method. The volume of equivalent sphere (V _e) was calculated to be 2.1×10^–19 cm³ for BSA with the intact disulfide bridges from the rotational correlation time. The value ofV _e was 4.4×10^–19 cm³ for the disulfide bridges-cleaved BSA. With an increase in SDS concentration, the rotational correlation time of the intact BSA became longer, while that of the disulfide bridges-cleaved BSA became shorter. This suggests that upon the binding of SDS, the total volume of the intact BSA increases while the expanded state of the protein, caused by the cleavage of the disulfide bridges, becomes compact.     

Labelling of sarcoplasmic reticulum membranes with 1-dimethylaminonaphthalene-5-sulfonyl chloride.

1. Sarcoplasmic reticulum membranes were labelled with 1-dimethylaminonaphtalene-5-sulfonyl chloride (DnsCl). Analyses of the dansylated membranes demonstrated that the most of the dye was associated with ATPase (ATP phosphohydrolase, EC 3.6.1.3) and phosphatidylethanolamine in the membranes. 2. Dansylation of the membranes could be performed without significant decrease in the ATPase activity. 3. Partial differentiation of fluorescence of Dns-phosphatidylethanolamine from that of Dns-ATPase could be achieved by changing excitation wavelength; Dns-ATPase emmitted in the shorter wavelength region, while Dns-phosphatidylethanolamine emmitted in the longer wavelength region. 4. Fluorescence polarization of the dye bound to the membranes indicated that both the ATPase and phosphatidylethanolamine were strongly immobilized in the membranes, while the ratio of freely rotating dye to the "frozen" dye bound to the ATPase was larger than that bound to the phosphatide.     

Competitive partial inhibitors of serum albumin-catalyzed sulfur cyanolysis

Efforts to locate the active site for sulfur cyanolysis catalyzed by bovine serum albumin have led to systematic tests of several compounds that inhibit the catalyzed reaction. Hexanoate and 5-dimethylaminonaphthalene-1-sulfonate bind at the same site and are partial inhibitors competitive with cyanide, uncompetitive with respect to sulfur. Various dansyl amino acids and 1-anilino-8-naphthalene sulfonate display the same inhibitory behavior but bis (1-anilino-8-naphthalene sulfonate) is a total inhibitor competitive with cyanide. These findings are interpreted to indicate that the cyanolysis active site is near, but not at, one of the short-chain fatty acid binding sites on albumin subdomain 2-AB or 3-AB. Both ionic repulsion and steric considerations are implicated in the mechanisms of inhibition.     

Kinetics of parasite cysteine proteinase inactivation by NO-donors

NO-donors block Plasmodium, Trypanosoma, and Leishmania life cycle inactivating parasite cysteine proteinases. In this study, the inactivation of falcipain, cruzipain, and Leishmania infantum cysteine proteinase by S-nitroso-5-dimethylaminonaphthalene-1-sulphonyl (dansyl-SNO), S-nitrosoglutathione (GSNO), (+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide (NOR-3), and S-nitrosoacetylpenicillamine (SNAP) is reported. With NO-donors in excess over the parasite cysteine proteinase, the time course of enzyme inactivation corresponds to a pseudo-first-order reaction for more than 90% of its course. The concentration dependence of the pseudo-first-order rate constant is second-order at low NO-donor concentrations but tends to first-order at high NO-donor concentrations. This behavior may be explained by a relatively fast pre-equilibrium followed by a limiting pseudo-first-order process. Kinetic parameters of cruzipain inactivation by GSNO were affected by the acidic pK shift of one ionizing group (from pKunl = 5.7 to pKlig = 4.8) upon GSNO-induced enzyme inactivation. Falcipain, cruzipain, and L. infantum cysteine proteinase inactivation by dansyl-SNO, GSNO, NOR-3, and SNAP is prevented and reversed by dithionite and l-ascorbic acid. However, the incubation of L. infantum cysteine proteinase with dansyl-SNO does not result in the appearance of fluorescence of the enzyme. More than 90% of the S-transnitrosylation product GSH existed in the inactivation reaction, suggesting that S-transnitrosylation is the favorite process for parasite cysteine proteinase inactivation. Furthermore, the fluorogenic substrate N-alpha-benzyloxycarbonyl-l-phenylalanyl-l-arginine-(7-amino-4-methylcoumarin) protects L. infantum cysteine proteinase from inactivation by SNAP. These results indicate that parasite cysteine proteinase inactivation by NO-donors occurs via NO-mediated S-nitrosylation of the Cys25 catalytic residue.     

Dansyl chloride labeling of Pseudomonas aeruginosa treated with pyocin R1: change in permeability of the cell envelope

Pyocin R1, a bacteriocin of Pseudomonas aeruginosa, caused an increase in binding of fluorescent label, 1-dimethylaminonaphthalene-5-sulfonyl chloride (dansyl chloride), to sensitive cells. In pyocin R1-treated cells, cytoplasmic soluble proteins and crude ribosomes as well as cell envelopes were labeled by dansyl chloride. The amount of bound dye was proportional to the multiplicity of pyocin R1 and reached a maximal level at high multiplicity. In addition, pyocin R1 rapidly caused an increase in fluorescence intensity of the hydrophobic probes N-phenyl-1-naphthylamine, pyrene, and perylene, which were mixed with cells. These results show that pyocin R1 damages locally a cell envelope barrier to hydrophobic solutes and allows dyes to penetrate into the intracellular space across the barrier.