Distribution in Rats Internal Organs of Intraperitoneally Given 125I-Labeled Heptapeptide [2-8]-Leucopyrokinin ([2-8]-LPK), a Truncated Analog of Insect Neuropeptide Leucopyrokinin.

Background: It was previously found that synthetic, insect-derived octapeptide leucopyrokinin (LPK) applied directly into the lateral brain ventricle induced a significant antinociceptive effect in rats. Its synthetic truncated analog heptapeptide [2-8]-leucopyrokinin displayed a stronger antinociceptive effect in comparison to native LPK. Moreover it was previously found a high accumulation of these both 125I-labeled peptides in adrenals, as well as in hypothalamus and in hippocampus of rats brain.

Effect of alloferon 1 on central nervous system in rats.

Alloferon 1 is an insect-derived peptide with potent antimicrobial and antitumor activity. It was isolated from blood of an experimentally infected insect, the blow fly Callifora vicina. Synthetic alloferon 1 reveals a capacity to stimulate activity of NK cells and synthesis IFN in animal and human models.

Further studies on the antiviral activity of alloferon and its analogues.

The subject of our studies was the synthesis, biological evaluation, and conformational studies of insect tridecapeptide alloferon (H-His-Gly-Val-Ser-Gly-His-Gly-Gln-His-Gly-Val-His-Gly-OH) and its analogues such as: [des-His(1) ]-, [Lys(1) ]-, [Arg(1) ]-, and [Ala(1) ]-alloferon. These peptides were synthesized to check the influence of the His residue at position 1 of the alloferon chain on its antiviral activity. Two aspects of the biological effects of these peptides were determined: (i) the cytotoxicity in vitro in the Vero, LLC-MK2, and HEp-2 cell lines, and (ii) the antiviral activity in vitro in respect to DNA and RNA viruses.

Studies of insect peptides alloferon, Any-GS and their analogues. Synthesis and antiherpes activity.

The subject of these studies was synthesis and determination of biological properties of a series of insect peptides, such as alloferon, Any-GS and their analogues. The synthesis of 14 peptides was performed by the solid-phase method. Biological effect of these peptides was evaluated by the antiviral test against Human Herpes Virus type 1 (HHV-1) in vitro using a Vero cell line.

Mononuclear copper(II) complexes of alloferons 1 and 2: a combined potentiometric and spectroscopic studies.

Mononuclear copper(II) complexes of the alloferon 1 His-Gly-Val-Ser-Gly-His-Gly-Gln-His-Gly-Val-His-Gly, alloferon 2 Gly-Val-Ser-Gly-His-Gly-Gln-His-Gly-Val-His-Gly, Ac-alloferon 1 Ac-His-Gly-Val-Ser-Gly-His-Gly-Gln-His-Gly-Val-His-Gly and Ac-alloferon 2 Ac-Gly-Val-Ser-Gly-His-Gly-Gln-His-Gly-Val-His-Gly have been studied by potentiometric, UV-vis, CD and EPR spectroscopic methods. The potentiometric and spectroscopic data shows that acetylation of the amino terminal group induces significant changes in the coordination properties of the Ac-alloferons 1 and 2 compared to the alloferons 1 and 2, respectively. The presence of four (Ac-alloferon 1) or three (Ac-alloferon 2) histidyl residues provides a high possibility for the formation of macrochelates via the exclusive binding of imidazole-N donor atoms.

Copper(II) complexes of Neobelliera Bullata Trypsin Modulating Oostatic Factor and its analogues.

The stoichiometry, stability constants and solution structure of the complexes formed in the reaction of copper(II) with hexapeptide NPTNLH, i.e. the Neobelliera Bullata Trypsin Modulating Oostatic Factor (Neb-TMOF), and its analogues DPTNLH, Ac-NPTNLH and Ac-DPTNLH have been determined by potentiometric, UV-visible, CD and EPR spectroscopic methods.

Structure-activity relationships for the cardiotropic action of the Led-NPF-I peptide in the beetles Tenebrio molitor and Zophobas atratus.

We have examined the effects of the Led-NPF-I peptide (Ala-Arg-Gly-Pro-Gln-Leu-Arg-Leu-Arg-Phe-amide) and a series of ten analogues on the heart contractile activity of Tenebrio molitor and Zophobas atratus, and the structure-activity relationships for cardioactive action of Led-NPF-I were established. A video microscopy technique and computer-based method of data acquisition and analysis were used to study the action of the peptides on continuously perfused heart preparations. Cardiac activity was progressively inhibited by Led-NPF-I when the peptide concentrations were increased from 10(-9) to 10(-5) M.

Plant signalling peptides: some recent developments.

The subject of this review is plant signalling peptides, peptides of a new generation which regulate growth, differentiation, and other plant physiological functions. These peptides include systemin, the phytosulfokines (PSKs), ENOD40, CLAVATA3, Locus-S, POLARIS, IDA, and ROT4. On the basis of literature data and our own results we discuss their structure, biological properties, and structure/biological function relationship, especially for the more studied systemin and PSK-alpha.

Insect gonadotropic peptide hormones: some recent developments.

Gonadotropic peptides are a new generation of peptide hormone regulators of insect reproduction. They have been isolated from ovaries, oviducts, or brains of insects. The subject of this paper is insect peptides that exert stimulatory or inhibitory effects on ovarian development and oocyte maturation.

Distribution of 125I-labeled [2-8]-leucopyrokinin, active analog of leucopyrokinin in rats.

The brain and internal organs distribution of 125I-labeled [2-8]-leucopyrokinin ([2-8]-LPK), a truncated analog of leucopyrokinin (LPK), an insect myotropic peptide injected into the lateral brain ventricle was determined in rats. A high accumulation of this analog in adrenals and in the hypothalamus and hippocampus of the brain was found. A lesser but significant [2-8]-LPK accumulation in other internal organs and parts of the brain was also observed.

Further analogues of plant peptide hormone phytosulfokine-alpha (PSK-alpha) and their biological evaluation.

Phytosulfokine-alpha (PSK-alpha), a sulfated growth factor of structure H-Tyr(SO3H)-Ile-Tyr(SO3H)-Thr-Gln-OH universally found in both monocotyledons and dicotyledons, strongly promotes proliferation of plant cells in culture. In studies on the structure/activity relationship of PSK-alpha the synthesis was performed of a series of a further 23 analogues modified in position 1, 3 or 4 as well as simultaneously in positions 1 and 3 of the peptide chain. Peptides were synthesized by the solid phase method according to the Fmoc procedure on a Wang-resin.

Plant peptide hormone phytosulfokine (PSK-alpha): synthesis of new analogues and their biological evaluation.

Phytosulfokine-alpha (PSK-alpha), a sulfated growth factor (H-Tyr(SO3H)-Ile-Tyr(SO3H)-Thr-Gln-OH) universally found in both monocotyledons and dicotyledons, strongly promotes proliferation of plant cells in culture. In our studies on structure/activity relationship in PSK-alpha the synthesis of a series of analogues was performed: [H-D-Tyr(SO3H)1]- (9), [H-Phe(4-SO3H)1]- (10), [H-D-Phe(4-SO3H)1]- (11), [H-Phg(4-SO3H)1]- (12), [H-D-Phg(4-SO3H)1]- (13), H-Phe(4-NHSO2CH3)1]- (14), [H-D-Phe(4-NHSO2CH3)1]- (15), [H-Phe(4-NO2)1]- (16), [H-D-Phe(4-NO2)1]- (17), [H-Phg(4-NO2)1]- (18), [H-D-Phg(4-NO2)1]- (19), [H-Hph(4-NO2)1]- (20), [H-Phg(4-OSO3H)1]- (21), [Phe(4-NO2)3]- (22), [Phg(4-NO2)3]- (23), [Hph(4-NO2)3]- (24), [H-Phe(4-SO3H)1, Phe(4-SO3H)3]- (25) [H-Phe(4-NO2)1, Phe(4-NO2)3]- (26), [H-Phg(4-NO2)1, Phg(4-NO2)3]- (27), [H-Hph(4-NO2)1, Hph(4-NO2)3]- (28) and [Val3]- PSK-alpha (29). For modification of the PSK-alpha peptide chain the novel amino acids and their derivatives were synthesized, such as: H-L-Phg(4-SO3H)-OH (1), H-D-Phg(4-SO3H)-OH (2), Fmoc-Phg(4-SO3H)-OH (3), Fmoc-D-Phg(4-SO3H)-OH (4), Boc-Phg(4-NHSO2CH3)-OH (5), Boc-D-Phg(4-NHSO2CH3)-OH (6) Boc-Phe(4-NHSO2CH3)-OH (7), and Boc-D-Phe(4-NHSO2CH3)-OH (8).

Leucopyrokinin (LPK) analog [d-Ala(5)]-[2-8]-LPK inhibits LPK-induced analgesia in rats.

It has been previously found in our laboratory that insect neuropeptide leucopyrokinin and [2-8]-leucopyrokinin, a truncated analog without the first aminoacid of leucopyrokinin peptide chain exert an antinociceptive effect in rats. The present study confirmed our previous results, and moreover it has been found that [d-Ala(5)]-[2-8]-leucopyrokinin, an analog of leucopyrokinin antagonized the antinociceptive effect of leucopyrokinin and of [2-8]-leucopyrokinin. We conclude that this synthetic analog is a probable leucopyrokinin antagonist.

Biological evaluation of analogues of an insect neuropeptide proctolin.

Continuing our studies on proctolin (Arg-Tyr-Leu-Pro-Thr) we performed the synthesis and biological evaluation of 52 analogues substituted in position 2, 3, 4, and 5 of the peptide chain. The peptides were bioassayed for cardiotropic activity in vitro on Tenebrio molitor and myotropic activity on foregut of Schistocerca gregaria. Twenty analogues retained 20-80% of proctolin activity.

The effect of poneratoxin on neuromuscular transmission in the rat diaphragm.

The effect of the ant venom neuropeptide--poneratoxin (PoTX)--on neuromuscular transmission in rat diaphragm tissue was studied by means of intracellular recordings of spontaneous miniature endplate potentials (MEPPs) and of nerve evoked endplate potentials (EPPs). A 2 microM concentration of PoTX caused a pronounced but transient increase in MEPPs frequency. Moreover, within the first few minutes of PoTX administration, the area, rise time and half decay time of MEPPs gradually decreased, reaching steady values after 15-20 min.