Isolation and characterization of a bradykinin potentiating peptide (BPP-S) isolated from Scaptocosa raptoria venom

Venom of the spider Scaptocosa raptoria was fractionated by chromatography on Sephadex G-10 followed by HPLC, and a bradykinin potentiating peptide, BPP-S, was obtained in pure form. The amino acid sequence of this undecapeptide is presented. Peptide BPP-S significantly potentiates the effects of bradykinin on smooth muscle, and inhibits the angiotensin-converting enzyme (ACE) in vitro.

Isolation and cardiovascular activity of a second bradykinin-related peptide ([Arg0, Trp5, Leu8]bradykinin) from trout

Previous work has shown that incubation of heat-denatured plasma from the rainbow trout Oncorhynchus mykiss with porcine pancreatic kallikrein generates [Lys0, Trp5, Leu8]bradykinin (trout [Lys0]BK). We have now isolated a second BK-related peptide from kallikrein-treated trout plasma with the primary structure: Arg-Arg-Pro-Gly-Trp-Ser-Pro-Leu-Arg (trout [Arg0]BK). Bolus injections of both trout [Arg0]BK and [Lys0]BK (> 100 pmol/kg) into the dorsal aorta of conscious trout produced multiphasic effects on arterial blood pressure. An initial pressor response of short duration (1-2 min) was followed by a fall in pressure (to below basal values in 11 out of 15 animals) and then by a sustained rise in pressure lasting up to 60 min. The maximum rise in pressure produced by trout [Arg0]BK (10 nmol/kg) was approximately one-fourth of the maximum rise produced by angiotensin II in the same animals. Intracerebroventricular injections of trout [Arg0]BK (500 pmol) into conscious trout had no effect on arterial blood pressure or heart rate. Trout [Arg0]BK did not affect the tension of vascular rings from trout efferent branchial and caeliacomesenteric arteries and anterior cardinal vein. Trout des [Arg9]BK had no effect on cardiovascular parameters, either in vivo or in vitro, indicating that the C-terminal arginine residue of the peptide is important in interaction with the trout kinin receptor(s).

Single cells as biosensors for chemical separations

A biosensor system based on the response of living cells was demonstrated that can detect specific components of a complex mixture fractionated by a microcolumn separation technique. This system uses ligand-receptor binding and signal-transduction pathways to biochemically amplify the presence of an analyte after electrophoretic separation. The transduced signal was measured by means of two approaches: (i) fluorescence determination of intracellular calcium concentrations in one or more rat PC-12 cells and (ii) measurement of transmembrane current in a Xenopus laevis oocyte microinjected with messenger RNA that encodes a specific receptor. This analysis system has the potential to identify biologically active ligands present in a complex mixture with exceptional sensitivity and selectivity.

Isolation and biological activity of [Trp5]bradykinin from the plasma of the phylogenetically ancient fish, the bowfin and the longnosed gar

The holostean fish occupy an important position in vertebrate phylogeny as extant representatives of a ancient group of ray-finned fish with evolutionary connections to present-day teleosts. Incubation of heat-denatured plasma from the bowfin Amia calva with trypsin generated bradykinin-like immunoreactivity. The primary structure of bowfin bradykinin was established as Ala-Pro-Pro-Gly-Trp-Ser-Pro-Phe-Arg. This amino acid sequence contains one amino acid substitution (Phe5 --> Trp) compared with mammalian bradykinin. The same peptide was generated in heat-denatured plasma from the longnosed gar Lepisosteus osseus. Treatment of plasma from either the bowfin or gar with glass beads under conditions previously shown to activate Factor XII in the plasma of mammals and reptiles did not generate bradykinin. Bolus injections of synthetic bowfin bradykinin (0.1, 0.3, and 1.0 nmol/kg) into the bulbus arteriosus of unanesthetized bowfin resulted in an immediate fall in arterial blood pressure of 5-10 min duration that was followed by a dose-dependent rise in pressure that was sustained for 30-60 min. There was no change in heart rate following bradykinin administration. The data suggest that the kallikrein-kinin system may predate the appearance of teleosts and may play a role in cardiovascular regulation in holosteans.

The effect of phytic acid on the resolution of peptides and proteins in capillary electrophoresis

Studies are reported on the effect of the sodium salt of phytic acid on the resolution of peptides and proteins. Improved separation in the case of peptides is shown to be due to ion-ion pairing interactions between the positively charged peptides and the phytic acid polyanionic species. The improved peak shapes related to the proteins can be interpreted in terms of the sample preconcentration due to injection of analytes from a water medium to one of high ionic strength.

Generation of [Ala1,Thr6]bradykinin in the plasma of a snake, the reticulated python

Incubation of heat-denatured plasma from the reticulated python, Python reticulatus with trypsin generated bradykinin-like immunoreactivity which was detected by radioimmunoassay using an antiserum raised against mammalian bradykinin. The primary structure of python bradykinin was established as Ala-Pro-Pro-Gly-Phe-Thr-Pro-Phe-Arg. This amino acid sequence contains two substitutions (Arg1-->Ala and Ser6-->Thr) compared with mammalian bradykinin. Treatment of python plasma with glass beads under conditions previously shown to generate [Thr6]bradykinin in the plasma of a turtle and an alligator did not generate bradykinin-like immunoreactivity. The data indicate that the plasma of a lepidosaur contains a kininogen but, unlike the plasma of chelonians and crocodilians, does not contain a prekallikrein activator related to Factor XII.

Poststatin, a novel inhibitor of bradykinin-degrading enzymes in rat urine

Incubation of bradykinin with rat urine resulted in the successive degradation of bradykinin to bradykinin-(1-8), bradykinin-(1-7) and bradykinin-(1-6). In contrast, in rat plasma, bradykinin was degraded via either bradykinin-(1-8) or bradykinin-(1-7) to bradykinin-(1-5). Phosphoramidon (1 mM) partially inhibited the degradation of bradykinin by rat urine, as well as the conversion of bradykinin-(1-7) to bradykinin-(1-6). D,L-2-Mercaptomethyl-3-guanidinoethylthiopropanoic acid (1 mM) and captopril (1 mM) did not have a significant effect on any of the degradation steps in rat urine. In contrast, all of the degradation steps in urine, namely, from bradykinin to bradykinin-(1-8), from bradykinin-(1-8) to bradykinin-(1-7) and from bradykinin-(1-7) to bradykinin-(1-6), were markedly inhibited by poststatin (1 mM), even though this compound was reported originally to be a novel inhibitor of post-proline cleaving enzyme. Poststatin (1 mM) did not inhibit the degradation of bradykinin in rat plasma. These results indicate that poststatin is an effective inhibitor of kinin-degrading enzyme in rat urine.

Purification and biological activity of alligator bradykinin

Incubation of plasma form the alligator (Alligator mississipiensis) with glass beads in the presence of a kininase inhibitor resulted in the activation of the kallikrein-kinin system and generation of bradykinin-like immunoreactivity. The kinin peptides were purified to homogeneity and were shown to comprise [Thr6]-bradykinin and des-Arg9[Thr6]bradykinin in the molar ratio of approximately 10:1. Bolus injections of synthetic [Thr6]bradykinin into the jugular vein of the anesthetized alligator resulted in a dose-dependent decrease in mean arterial blood pressure. The minimum dose of kinin producing a significant fall in pressure was 0.07 micrograms/kg body wt and the maximum response (25 +/- 6% fall; mean +/- SD, n = 8) was produced by a dose of 0.56 micrograms/kg body wt. The dose producing a half-maximum response was 0.19 +/- 0.08 micrograms/kg. The data indicate that alligator plasma contains all the components of the kallikrein-kinin system found in mammals and suggest that the system may be of physiological importance in the regulation of cardiovascular function in these reptiles.

Effect of direct control of electroosmosis on peptide and protein separations in capillary electrophoresis

The separations of peptide and protein mixtures in capillary zone electrophoresis (CZE) at various solution conditions were studied with the direct control of electroosmosis. The zeta potential at the aqueous/capillary interface and the resulted electroosmosis in the presence of an electric field were directly controlled by using an additional electric field applied from outside of the capillary. The controlled electroosmotic flow affected the migration time and zone resolution of peptide and protein mixtures. The changes in the magnitude and polarity of the zeta potential caused the various degrees of peptide and protein adsorption onto the capillary through the electrostatic interactions. The separation efficiencies of peptide and protein mixtures were enhanced due to the reduction in peptide and protein adsorption at the capillary wall. The direct manipulations of the separation efficiency and resolution of peptide and protein mixtures in CZE were demonstrated by simply controlling the zeta potential and the electroosmotic flow with the application of an external electric field.

Ile-Ser-bradykinin is an aberrant permeability factor in various human malignant effusions

In this study we provide evidence for the presence of the aberrant peptide, Ile-Ser-bradykinin, in various human malignant exudates. The peptide was detected by deproteinisation of the effusion, application to reversed-phase HPLC, collection of the fractions containing Ile-Ser-bradykinin (retention time 6.90 min), degradation with carboxypeptidase B, and rechromatography of the resulting des-Arg-Ile-Ser-bradykinin (des-Arg-ISB) (retention time 13.5 min). In addition, all positive samples were confirmed by amino acid analysis and most of them (7/8) by amino-acid sequencing. In malignant effusions from 8 patients out of a group of 113 patients, Ile-Ser-bradykinin was found in concentrations between 12 and 520 mumol. In 44 malignant effusions, Ile-Ser-bradykinin was suspected, but could not be confirmed by the required additional methods (amino-acid analysis, sequencing) because of its low concentration. Sixty eight benign effusions were negative for Ile-Ser-bradykinin.

Purification and characterization of bioactive peptides from skin extracts of Rana esculenta

The peptide fraction extracted by methanol from the skin of Rana esculenta, a species widely distributed in Western Europe, was investigated. The pharmacological activity found in the extract is attributable to the presence of authentic bradykinin, together with a shorter, partially active version of this molecule, des-Arg9-bradykinin. Also the bradykinin fragment 1-7 has been isolated, but it was inactive in our bioassay system. Moreover, a family of hydrophobic peptides has been purified and characterized, which appeared devoid of pharmacological activities when tested on smooth muscle preparations, but were provided with hemolytic activities.

Bradykinin and kininogens in bovine milk

Two peptides exhibiting kinin activity in an isolated rat uterus assay were purified from pasteurized skim bovine milk. The amino acid sequence of the more prominent peptide was found to be that of bradykinin. Partially purified kinin preparations were also obtained from N-tosyl-L-phenylalanyl chloromethyl ketone-treated trypsin digests of non-fat dry milk and insoluble lactalbumin. The application of fast atom bombardment/mass spectrometry permitted detection of the bradykinin protonated molecular ion in each of these samples. Collision-activated decomposition of the ion of m/z 1061 confirmed it to be the protonated molecular ion of bradykinin. Fast atom bombardment/mass spectrometry analysis further confirmed the occurrence of bradykinin in a pancreatic kallikrein digest of a partially purified bovine milk kininogen preparation. In apparent contrast with bovine plasma kininogens, the forms of kininogen which occur in milk include a high Mr kininogen (Mr greater than 68,000) and a low Mr kininogen (Mr 16,000-17,000). Kinin formation from the high Mr kininogen is catalyzed by porcine pancreatic kallikrein or trypsin.

A novel kinin, Met-Ile-Ser-bradykinin (Met-T-kinin) is released from T-kininogen by an acid proteinase of granulomatous tissues in rats

Acid proteinase of granulomatous tissues in rats with carrageenin-induced inflammation released two types of kinin from T-kininogen. The kinin was identified as Ile-Ser-bradykinin (T-kinin) and a novel kinin, Met-Ile-Ser-bradykinin (Met-T-kinin), from determination of its amino acid composition and its immunoreactivity toward anti-bradykinin antiserum. The release of T-kinin and Met-T-kinin from T-kininogen were found to occur by consecutive cleavage by cathepsin D and 72 kDa protease.

Quantification, isolation and structural determination of bradykinin and hydroxyprolyl-bradykinin in tumor ascites

The presence of kinins in ascitic tumor fluids from rodents and human patients was identified and quantified. In bioassay, kinin content was found to be 1 to 40 ng/ml, and by enzyme immunoassay, 0.6 to 2.5 ng/ml. In particular, a high kinin content, 40 ng/ml, was found in the ascites of a gastric cancer patient by bioassay. Purification of this kinin in the ascites from the gastric cancer patient was performed by ethanol precipitation, gel filtration and reversed-phase high-performance liquid chromatography (HPLC). Two peaks (peak A and peak B) showed kinin activity. Peak A did not correspond to either bradykinin or other known kinins, such as lysyl-bradykinin and T-kinin, whereas peak B corresponded to bradykinin. Peak A contained 8 amino acid residues from bradykinin minus one proline plus an additional hydroxyproline. Sequence analysis of peak A showed that the proline at the third amino acid residue of bradykinin was replaced by hydroxyproline. The retention time of peak A on reversed-phase HPLC was exactly the same as that of synthetic hydroxyprolyl3-bradykinin (Hyp3-bradykinin) but was distinguishable from des-Pro3-bradykinin. Thus, these results demonstrate for the first time the presence of Hyp3-bradykinin in mammalian system.

Purification and identification of [hydroxyprolyl3]bradykinin in ascitic fluid from a patient with gastric cancer

Kinins in the ascitic fluid from a patient with gastric cancer were purified by gel filtration and reversed-phase high-performance liquid chromatography (HPLC). Two fractions (fractions I and II) showed kinin activity. Fraction I did not correspond to either bradykinin or other known kinins, whereas fraction II corresponded to bradykinin. Fraction I contained 8 amino acid residues from bradykinin minus 1 proline plus 1 additional hydroxyproline. Sequence analysis of fraction I showed that the proline at the third amino acid residue of bradykinin was replaced by hydroxyproline. The retention time of fraction I on reversed-phase HPLC was exactly the same as that of synthetic [hydroxyprolyl3]bradykinin (Arg-Pro-Hyp-Gly-Phe-Ser-Pro-Phe-Arg) and was distinguishable from des-Pro3-bradykinin. Thus, these results demonstrate for the first time the presence of [hydroxyprolyl3]bradykinin in vivo. This is also the first report of the presence of bradykinin in human tumor ascites.

Hydroxyprolyl3-bradykinin in high molecular mass kininogen. Presence in human and monkey kininogens, but not in kininogens from bovine, rat, rabbit, guinea pig and mouse plasmas

The contents of hydroxyprolyl3-bradykinin in high molecular mass (HMM) kininogens from human and animal plasmas were examined by reversed-phase HPLC following their proteolytic scission by bovine plasma kallikrein. The relative contents of hydroxyprolyl3-bradykinin in kinins from HMM kininogens from pooled plasmas of human and monkey origin were 33 and 73%, respectively. On the other hand, hydroxyprolyl3-bradykinin could not be detected in HMM kininogen preparations from bovine, rat, guinea pig, rabbit and mouse plasmas. Hydroxyproline in hydroxyprolyl3-bradykinin was assigned as trans-4-hydroxyproline by comparison of the retention times on reversed-phase HPLC with isomers of hydroxyproline after derivatization with 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole chloride.

High-performance liquid chromatographic analysis of arginine-containing peptides in biological fluids by means of a selective post-column reaction with fluorescence detection

Highly sensitive and specific high-performance liquid chromatographic methodology for the fluorescence detection of arginine-containing peptides in biological matrices is described. Following HPLC separation, a post-column reaction of the guanidino group of the arginine moiety with ninhydrin under basic conditions is utilized to generate a fluorescent peptide product which can be measured at high sensitivity. Careful optimization of the post-column reaction conditions, and the use of HPLC columns of reduced internal diameter, resulted in on-column detection limits as low as 50 fmol. Application to the determination of synthetic arginine-containing vasopressin antagonists in human plasma resulted in a quantitative response which is linear over the range 0.5-100 pmol/ml. The assay method is sufficiently sensitive, accurate, and precise for use in pharmacokinetic studies of these synthetic peptides. The methodology also has general applicability in the detection of naturally occurring arginine-containing peptides.

Identification of T-kinin-Leu(T-kinin-containing peptide) released from T-kininogen by cathepsin D of granulomatous tissues in rats

Acid proteinases of granulomatous tissues in rats with carrageenin-induced inflammation released kinin from T-kininogen. By column chromatography on pepstatin-Sepharose 4B, two types of acid proteinase seems to be responsible for kinin release. One of the acid proteinase was identified as cathepsin D from SDS-polyacrylamide gel electrophoresis and Western-blot analysis, using anti-rat liver cathepsin D IgG. Cathepsin D alone could not release T-kinin, but T-kinin-containing peptides. The T-kinin-containing peptides were separated into two peptides by reverse-phase high-performance liquid chromatography. From determination of its amino acid composition and its immunoreactivity toward anti-bradykinin antiserum, one of the T-kinin-containing peptides was identified as T-kinin-Leu.

Ile-Ser-bradykinin (T-kinin) and Met-Ile-Ser-bradykinin (Met-T-kinin) are released from T-kininogen by an acid proteinase of granulomatous tissues in rats

An acid proteinase of granulomatous tissues in rats with carrageenin-induced inflammation released kinin from T-kininogen. The kinin isolated by n-butanol extraction was separated by reverse-phase high-performance liquid chromatography into T-kinin and a T-kinin derivative. From determination of its amino acid composition and its immunoreactivity toward anti-bradykinin antiserum, the T-kinin derivative was identified as Met-Ile-Ser-bradykinin (Met-T-kinin).

Comparison of reversed-phase and cation-exchange high-performance liquid chromatography for separating closely related peptides: separation of Asp76-human parathyroid hormone (1-84) from Asn76-human parathyroid hormone (1-84)

Cation-exchange high-performance liquid chromatography (CE-HPLC) was compared with ordinary reversed-phase high-performance liquid chromatography (RP-HPLC) for separating closely related peptides. Some synthetic samples of bradykinin and angiotensins, which were homogeneous according to RP-HPLC, were found to be inhomogeneous when analyzed by CE-HPLC. On the other hand, diastereomeric peptides could be separated much more efficiently by RP-HPLC than by CE-HPLC. These results indicated that the purity of synthetic peptides should be checked not only by RP-HPLC but also by ion-exchange HPLC. In the case of human parathyroid hormone (hPTH), baseline separation of Asp76-hPTH from Asn76-hPTH by RP-HPLC was not possible, but was by CE-HPLC. Using this method we confirmed that the Asn residue in hPTH at position 76 could not be converted into the Asp residue under the conditions used to isolate and purify it from human organs.

Increased levels of new spasmogenic substances released by trypsin from plasma of hypertensive rats

The present study was undertaken to evaluate the participation of the kallikrein-kinin system in the normalization of blood pressure after release of the clip in one-kidney, one clip hypertensive rats ( 1K1C ). Kininogen was determined before and after unclipping by tryptic digestion of denatured rat plasma, and spasmogenic activity was measured with isolated guinea pig ileum. In contrast to human plasma for which bradykinin (BK) is the only trypsin-releasable spasmogenic substance ( TRSS ), rat plasma contains non-BK TRSS (Fractions P1 and P2) as well as BK. Fractions P1 and P2 were separated from BK by SP-Sephadex chromatography. An increase of total TRSS was demonstrated 60 days after clipping and reached a maximum at approximately Day 75, which was two times that of the normotensive controls (NC). The level of total TRSS did not change after unclipping . The increased level of TRSS in the hypertensive state confirmed the observations of other investigators who reported increased kininogen levels but who could not distinguish between BK and non-BK TRSS because bioassays were performed without prior chromatographic separation of the spasmogenic activities. Fractions P1 and P2 were present in the TRSS of both 1K1C and NC plasma, but were two to six times higher in 1K1C and thus probably accounted quantitatively for the increased TRSS in 1K1C . The data suggest that in the hypertensive state there is an alteration in the relative amounts of some plasma proteins that contain non-BK TRSS within their amino acid sequences. Fractions P1 and P2 also contain potentiating peptides and have not yet been purified to homogeneity.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation and structure of T-kinin

T-kinin, a previously undescribed peptide containing bradykinin, has been isolated following treatment of rat plasma with trypsin (1 mg/ml). The liberated T-kinin, which contracts the rat uterus, was isolated by procedures including OM-cellulose, Biogel P-4 and reverse-phase high-performance liquid chromatography. The final material had a single N-terminal isoleucine and was shown by amino acid analysis and sequence determination to have the structure of the undecapeptide Ile-Ser-Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg (isoleucyl-seryl-bradykinin). The relationships of the protein from which T-kinin is cleaved (T-kininogen) to other known kininogens is discussed.