Isolation and characterization of two forms of an acidic bromelain stem proteinase.

Two forms of an acidic bromelain proteinase isolated from crude bromelain, an extract from pineapple stem, were found by a two-step FPLC purification procedure. The basic main components were removed by cation exchange chromatography and the breakthrough fraction was further resolved by anion exchange chromatography into 15 protein fractions, only two of which, called SBA/a and SBA/b, were proteolytically active. These components were characterized by electrospray mass spectroscopy (ESMS), isoelectric focusing, N-terminal amino acid sequence analysis, monosaccharide analysis, and enzymatic parameters. The molecular masses of SBA/a and SBA/b were determined by ESMS to be 23,550 and 23,560, respectively. The isoelectric points (pI) of the two bands of SBA/a were 4.8 and 4.9; SBA/b focused as a single band at pI = 4.8. Partial N-terminal amino acid sequences (11 residues) were identical to SBA/a and SBA/b and identical with those of stem bromelain, the basic main proteinase of the pineapple stem, and fruit bromelain, the acidic main proteinase of the pineapple fruit. Both components are highly glycosylated; hydrolysis of SBA/a yielded about twofold more monosaccharide per protein than SBA/b. The comparison of the catalytic properties of SBA/a with those of SBA/b revealed no relevant differences in the hydrolysis of three peptidyl-NH-Mec substrates and in the inhibition profiles using chicken cystatin and E-64, indicating that these components can be considered as two forms of a single enzyme. Both forms are scarcely inhibited by chicken cystatin and slowly inactivated by E-64, hence are nontypical cysteine proteinases of the papain superfamily.

Hair concentrations and self-reported abuse history of 20 amphetamine and ecstasy users.

Hair samples of 20 volunteers of the techno-music scene, who more or less regularly consumed ecstasy tablets and speed and anonymously reported their abuse history, were analyzed in one to seven 3 cm segments for amphetamine (A), methamphetamine (MA), methylenedioxyamphetamine (MDA), methylenedioxymethamphetamine (MDMA), methylenedioxyethamphetamine (MDE) and N-methyl-1-(1,3-benzodioxol-5-yl)-2-butylamine (MBDB) by digestion in 1 M NaOH, subsequent extraction with C18 Bond Elut columns, derivatization with pentafluoropropionyl anhydride and GC/MS-SIM measurements using deuterated standards of A, MA, MDA and MDMA. The concentrations were in the regions 0.1 to 4.8 ng/mg for A (17 samples), 0.05 to 0.89 ng/mg for MDA (16 samples), 0.1 to 8.3 ng/mg for MDMA (16 samples), 0.12 to 15 ng/mg for MDE (13 samples) and 0.21 to 1.3 ng/mg for MBDB (2 samples). MA was not detected. For comparison the frequency and the concentration of these drugs in 124 different ecstasy tablets were determined by HPLC. The drug concentration in the hair segments were compared with the volunteers' reports. Despite the enormous interindividual differences qualitatively an increase of the total concentration of MDA, MDMA and MDE in the proximate 3 cm segments with increasing ecstasy abuse frequency during the last three month before sampling is recognized. In the individual comparison with the chronological consumer reports in most cases a longer interruption or a change of the abuse intensity is not clearly seen at the segment concentrations. As a reason the incorporation of the drugs from sweat into elder hair regions and the slow removal by washing are discussed.

Isolation and partial characterization of basic proteinases from stem bromelain.

Crude bromelain extracts from pineapple stems (Ananas comosus) were fractionated by two-step FPLC-cation-exchange chromatography. At least eight basic proteolytically active components were detected. The two main components F4 and F5 together with the most active proteinase fraction F9 were characterized by SDS-PAGE, mass spectroscopy, multizonal cathodal electrophoresis, partial amino acid sequence, and monosaccharide composition analysis. F9 amounts to about 2% of the total protein and has a 15 times higher specific activity against the substrate L-pyroglutamyl-l-phenylanalyl-l-leucine-p-nitroanilide (PFLNA) than the main component F4. The molecular masses of F4, F5, and F9 were determined to 24,397, 24,472, and 23,427, respectively, by mass spectroscopy. Partial N-terminal amino acid sequence analysis (20 amino acids) revealed that F9 differs from the determined sequence of F4 and F5 by an exchange at position 10 (tyrosine-->serine) and position 20 (asparagine-->glycine). F4 and F5 contained fucose, N-acetylglucosamine, xylose, and mannose in ratio of 1.0:2.0:1.0:2.0, but only 50% of the proteins seem to be glycosylated, whereas F9 was found to be unglycosylated. Polyclonal antibodies (IgG) against F9 detected F4 and F5 with tenfold reduced reactivity. The pH optimum of F4 and F5 was between pH 4.0 and 4.5 and for F9 close to neutral pH. The kinetic parameters for PFLNA hydrolysis were similar for F4 (Km 2.30 mM, kcat 0.87 sec-1 and F5 (Km 2.42 mM, kcat 0.68 sec-1), and differed greatly from F9 (Km 0.40 mM, kcat 3.94 sec-1).

Bromelain protease F9 reduces the CD44 mediated adhesion of human peripheral blood lymphocytes to human umbilical vein endothelial cells.

The thiol protease bromelain has been shown to remove T-cell CD44 molecules from lymphocytes and to affect T-cell activation. We investigated the effect of a highly purified bromelain protease F9 (F9) on the adhesion of peripheral blood lymphocytes (PBL) to human umbilical vein endothelial cells (HUVEC). Preincubation of the lymphocytes with F9 reduced the adherence to about 20% of unstimulated and to about 30% of phorbol-dibutyrate (P(Bu)2) stimulated lymphocytes. Using flow cytometry, both crude bromelain and protease F9 reduced the expression of CD44, but not of LFA-1, on PBL. F9 was about 10 times more active than crude bromelain; at 2.5 micrograms/ml of F9 about 97% inhibition of CD44 expression was found. A mAb against CD44 was tested and found to block the F9-induced decrease in PBL-binding to HUVEC. The results indicate that F9 selectively decreases the CD44 mediated binding of PBL to HUVEC.

Bromelain proteinase-f9 augments human lymphocyte-mediated growth-inhibition of various tumor-cells in-vitro.

Bromelain, a crude extract from pineapple stem containing various thiol proteases, has previously been suggested for adjuvant therapy of malignant diseases. We hence tested in vitro whether a highly purified bromelain proteinase (F9) would affect the antitumor activity by human peripheral blood lymphocytes (PBL) against MCF-7 breast cancer, KB squamous carcinoma and SK-MEL-28 melanoma cells. The antiproliferative effects by pretreated PBL were determined using the microculture tetrazolium (MTT) assay. All three cell lines were susceptible to F9-treated PBL and KB cells were selected to examine the kinetics, the dose dependency and the specificity of the F9 effects on PBL. Maximal antitumor effects were obtained when PBL were incubated with 25 mug/ml of F9 for 3 days at which the proteolytical activity of the added F9 was 1.6 U/mg. The F9-induced PBL antitumor activity was dependent on the applied proteolytical activity and abolished when F9 was inactivated by iodoacetamide. In contrast to F9, trypsin or pronase were not able to induce PBL-mediated growth inhibition of KB target cells. In response to F9, the concentration of interleukin-2 (IL-2) and tumor necrosis factor-a increased 10 and 19 fold in the PBL supernatant, respectively. F9 was found to synergize LAK cell activity in addition to suboptimal concentrations (0.625-2.5 U/ml) of rIL-2. In contrast to rIL-2-activated PBL, no cytolytic effect by F9-activated PBL was measured in the BCECF release assay, suggesting that F9 acts by a mechanism different from that of IL-2. F9 was also found to be growth inhibitory in the MTT assay, when it was directly added to the tumor cells: The concentration, at 50% growth inhibition by F9, was in the range of 25-38 mug/ml at which the proteolytical activity of the added F9 was 2.5 U/mg. On the basis of the present study we suggest that F9 alone, or in combination with rIL-2, may be used as a potential biological response modifier in specific immunotherapy of distinct cancer diseases.

Bromelain proteinases modulate the cd44 expression on human molt-4/8 leukemia and sk-mel-28 melanoma-cells in-vitro.

CD44 cell surface proteins are involved in leukocyte binding to endothelium and the metastatic spread of tumor cells. Using flow cytometric analysis (FCMA), we investigated the effects of the proteases bromelain, papain, trypsin, and chymotrypsin on the density of CD44 molecules present on human leukemia Molt 4/8 cells. Bromelain was found to be most active in reducing CD44 receptor density. In addition, the effects of the purified bromelain proteinases F4 and F9 were investigated. On Molt 4/8 cells crude bromelain and F9, with the highest proteolytical activity, were found to be most active in reducing CD44 receptor density with a half maximal value of 1.9 mu g/ml and 2.3 mu g/ml, respectively. On human SK-Mel 28 melanoma cells especially F9 showed a strong effect, with a half maximal value of 1.5 mu g/ml. The implications of the findings are discussed with view of the reported antimetastatic activity of orally administrated bromelain with respect to CD44.