Human heat shock protein 60 (409-424) fragment is recognized by serum antibodies of patients with acute coronary syndromes.

Acute coronary syndromes (ACS), including unstable angina (UA) and acute myocardial infarction (MI), are clinical manifestations of a progressive atherosclerotic process. Antibodies (Ab) to heat shock proteins (hsp) have been reported to be associated with atherosclerosis. Blood samples from 35 patients with ACS and 20 healthy volunteers were tested for Ab to human hsp60 by an enzyme-linked immunosorbent assay (ELISA).

Chemical synthesis and kinetic study of the smallest naturally occurring trypsin inhibitor SFTI-1 isolated from sunflower seeds and its analogues.

The smallest known naturally occurring trypsin inhibitor SFTI-1 (14 amino acid residues head-to-tail cyclic peptide containing one disulfide bridge) and its two analogues with one cycle each were synthesized by the solid phase method. Their trypsin inhibitory activity was determined as association equilibrium constants (K(a)). Additionally, hydrolysis rates with bovine beta-trypsin were measured.

Cytokine-inducing activity of a proline-rich polypeptide complex (PRP) from ovine colostrum and its active nonapeptide fragment analogs.

A complex of proline-rich polypeptides (PRP) was isolated from ovine colostrum in our laboratory and was shown to possess immunomodulatory properties and psychotropic activity, including beneficial effects in the treatment of Alzheimer's disease. A nonapeptide fragment (NP): Val-Glu-Ser-Tyr-Val-Pro-Leu-Phe-Pro, isolated from the chymotryptic digestion products of PRP, and its C-terminal fragment, a hexapeptide (HP): Tyr-Val-Pro-Leu-Phe-Pro also exhibited immunoregulatory activity. Although NP and HP expressed activity similar to that of PRP in studies on humoral and cellular immune responses, in other immune processes, e.

Chromogenic substrates of bovine beta-trypsin: the influence of an amino acid residue in P1 position on their interaction with the enzyme.

The Cucurbita maxima trypsin inhibitor CMTI-III molecule was used as a vehicle to design and synthesize a series of trypsin chromogenic substrates modified in position P1: Ac-Ala-Val-Abu-Pro-X-pNA, where X = Orn, Lys, Arg, Har, Arg(NO(2)), Cit, Hci, Phe(p-CN), Phe(p-NH(2)); pNA = p-nitroanilide. The most active compounds (as determined by specificity constant k(cat)/K(m)) were peptides with the Arg and Lys residues in the position discussed. Changes in the length and the decrease of the positive charge of the amino acid residue side chain in position P(1) resulted in the decrease or loss of the affinity towards bovine beta-trypsin.

The effect of statherin and its shortened analogues on anaerobic bacteria isolated from the oral cavity.

The susceptibility (MIC) of 44 strains of anaerobic bacteria isolated from the oral cavity and 3 standard strains to statherin and its C-terminal fragments with sequences QYQQYTF, YQQYTF, QQYTF, QYTF and YTF was determined by means of plate dilution technique in Brucella agar with 5% content of defibrinated sheep's blood, menadione and hemin. The culture was anaerobic. As shown, at concentrations from 12.

Specific induction of Z-DNA conformation by a nuclear localization signal peptide of lupin glutaminyl tRNA synthetase.

Recently we have sequenced cDNA of plant glutaminyl-tRNA synthetase (GlnRS) from Lupinus luteus. At the N terminal part the protein contains a lysine rich polypeptide (KPKKKKEK), which is identical to a nuclear localization signal (NLS). In this paper we showed that two synthetic peptides (20 and 8 amino acids long), which were derived from lupin GlnRS containing the NLS sequence interact with DNA, but one of them (8aa long) changing its conformation from the B to the Z form.

Design, chemical synthesis and kinetic studies of trypsin chromogenic substrates based on the proteinase binding loop of Cucurbita maxima trypsin inhibitor (CMTI-III).

A series of trypsin chromogenic substrates with formula: Y-Ala-X-Abu-Pro-Lys-pNA, where X = Gly, Ala, Abu, Val, Leu, Phe, Ser, Glu and Y = Ac, H; pNA = p-nitroanilide was synthesized. The Cucurbita maxima trypsin inhibitor CMTI-III molecule was used as a vehicle to design the trypsin substrates. To evaluate the influence of position P(4) on the substrate-enzyme interaction, kinetic parameters of newly synthesized substrates with bovine beta-trypsin were determined.

Studies on binding of HIV-1 p24gag peptide to HLA-Cw3+ cells.

Human major histocompatibility complex class I antigens, HLA-C, are expressed on the cell surface at approximately a tenfold lower level than HLA-A and -B. We hypothesized that the expression of HLA-C is limited by the quantity of high affinity peptides which bind to these molecules, thus allowing only a small fraction of HLA-C molecules to be transported and/or to remain stable on the cell surface. If this assumption is correct, then the addition of exogenous peptide should increase cell surface HLA-C expression.

Modifications outside the proteinase binding loop in Cucurbita maxima trypsin inhibitor III (CMTI-III) analogues change the binding energy with bovine beta-trypsin.

Five 26-peptide analogues of the trypsin inhibitor [Pro18]CMTI-III containing Leu or Tyr in position 7 and Val or Tyr in position 27: 1 (Leu7, Tyr27), 2 (Tyr7, Val27), 3 (Tyr7, Tyr27), 4 (Leu7, Val27) and 5 (Leu7, Ala18, Tyr27) were synthesized by the solid-phase method. Analogues 1-4 displayed Ka with bovine beta-trypsin of the same order of magnitude as the wild CMTI-III inhibitor, whereas for analogue 5, this value was lower by about 3 orders of magnitude. This indicated that for the analogues with Pro (but not with Ala) in position 18, the side-chain interactions between positions 7 and 27 did not play a critical role for the stabilization of the active structure.

Antiserum against connexin32 fragment reacts with a 32-kD protein localised in gap junctions of mouse and rat liver, endometrium and in the fish heart.

The expression of various connexins so far identified is metabolically and developmentally regulated. Examples include uterine endometrium where the expression of gap junction protein, connexin32 (Cx32) is regulated by steroid hormones. In this study we attempted to synthesise a short peptide which matches the portion of the amino acid sequence of the Cx32.

Effect of colostrinin, an immunomodulatory proline-rich polypeptide from ovine colostrum, on sialidase and beta-galactosidase activities in murine thymocytes.

Colostrinin: a proline-rich polypeptide (PRP) from ovine colostrum and its nonapeptide active fragment (NP) induce maturation and differentiation of murine thymocytes, formation of helper cells from PNAhigh thymocytes and cytotoxic T cells from PNAlow thymocytes. These processes are accompanied by changes in expression of receptors for peanut agglutinin (PNA), PNAhigh thymocytes were transformed into PNAlow cells, and vice versa. It was shown, in various laboratories, that sialyltransferases are involved in the transformation of PNAhigh thymocytes into PNAlow cells.

Distance between the basic group of the amino acid residue's side chain in position P1 of trypsin inhibitor CMTI-III and Asp189 in the substrate pocket of trypsin has an essential influence on the inhibitory activity.

Three new analogues of trypsin inhibitor CMTI-III were synthesized by the solid-phase method: [Lys5]-CMTI-III, [Orn5]CMTI-III and [Dab5]CMTI-III. Only one analogue with L-lysine residue in position P1 showed inhibitory activity of the same order of magnitude as did wild CMTI-III. Two remaining analogues were completely inactive.

Influence of L-naphthylalanine in position 3 of AVP and its analogues on their pharmacological properties.

We describe the synthesis and pharmacological properties of two series of analogues: one which consists of three peptides having L-1-naphthylalanine in position 3 and the second composed of analogues substituted in position 3 with L-2-naphthylalanine. All peptides were tested in bioassays for pressor and antidiuretic activities. We also checked the uterotonic activity in vitro.

Interaction of HIV Tat model peptides with tRNA and 5S rRNA.

New data are presented on the interaction of model synthetic peptides containing an arginine-rich region of human immunodeficiency virus (HIV-Tat), with native RNA molecules: tRNA(Phe) of Saccharomyces cerevisiae and 5S rRNA from Lupinus luteus. Both RNA species form complexes with the Tat1 (GRKKRRQRRRA) and Tat2 (GRKKRRQRRRAPQDSQTHQASLSKQPA) peptides, as shown by electrophoretic gel shift and RNase footprint assays, and CD measurements. The nucleotide sequence UGGG located in the dihydrouridine loop of tRNAPhe as well as in the loop D of 5S rRNA is specifically protected against RNases.

Specific interactions of Cu2+ ions with fragments of envelope protein of hepatitis B virus.

Potentionmetric and spectroscopic (EPR, CD and absorption spectra) data have shown that a fragment of envelope proteins of the hepatitis B virus could be very specific bind molecules for Cu2+ ions using arginine lateral NH2 donor sites. The presence of Pro and Asp residues makes Arg binding not only very specific, but also very efficient.

Surprising pharmacological activity of analogues designed by substitution of position 3 in arginine vasopressin (AVP) and 8-D-arginine vasopressin with L-2-napthylalanine.

In an attempt to develop more active and selective analogues of arginine vasopressin (AVP), two peptides have been designed, synthesized and tested for vasopressor (V1-receptors) and antidiuretic (V2-receptors) activities. We also estimated the uterotonic and anti-uterotonic activities of these compounds in-vitro. The first peptide, [(L-2-Nal)3] AVP is a highly active V2-agonist.

Fluorescence and Monte Carlo conformational studies of the (1-15) galanin amide fragment.

Galanin (GAL) is a 29 amino acid C-terminally aminated linear neuropeptide showing diverse biological activities. The N-terminal (1-15)GAL-NH2 fragment was shown to have a very high affinity to the galanin receptor. In this work we describe the results of a combined fluorescence and Monte Carlo studies, the latter carried out using the ECEPP/3 force field with and without including hydration, on the (1-15)GAL-NH2 fragment.

Mechanism of the activation of proteinase inhibitor synthesis by systemin involves beta-sheet structure, a specific DNA-binding protein domain.

We analyzed a tertiary structure of systemin, the first identified polypeptide plant hormone, using two-dimensional NMR spectroscopy. From these data and molecular dynamics calculations we concluded that the peptide can adopt a Z-like-beta-sheet structure, which has previously been found in many specific DNA-binding proteins. Using DNA-cellulose affinity chromatography, we showed that systemin binds strongly to DNA.

Cu(II) binding by angiotensin II fragments: Asp-Arg-Val-Tyr-Ile-His and Arg-Val-Tyr-Ile-His. Competition between amino group and imidazole nitrogens in anchoring of metal ions.

Potentiometric and spectroscopic (absorption, circular dichroism and electron paramagnetic resonance) study on the coordination of two angiotensin II fragments (Asp-Arg-Val-Tyr-Ile-His and Arg-Val-Tyr-Ile-His) to Cu(II) ions has shown that competition between amino and imidazole nitrogens to anchor metal ions is a complicated process and may lead to formation of macrochelate rings. The important factor that influences this competition is the distance between competing His and N-terminal residues (number of spacer residues in a peptide sequence).

Thermoregulatory activity of sodium nitroprusside and arginine vasopressin.

1. Thermal responses to sodium nitroprusside (SNP, 3 mg/kg/hr) and arginine vasopressin (AVP, 3 micrograms/kg) were investigated in normothermic and febrile rabbits (LPS, 1 microgram/kg) at ambient temperature of 20.0 +/- 1.

Intracerebroventricular galanin and N-terminal galanin fragment enhance the morphine-induced analgesia in the rat.

Behavioral effect of galanin and its fragments, galanin1-15 and galanin16-29 (200 ng, 1 and 5 micrograms), after intracerebroventricular (i.c.v.

Structure--function studies of vasopressin analogues with D-3 pyridyl-alanine in position 2.

A number of analogues of vasopressin, incorporating the substitution of D-3'-(pyridyl)-alanine in position 2, were synthesized and tested for antidiuretic (V2), vasoconstrictor (V1a) and ACTH secretory (V1b; pituitary) activities. One analogue, deamino-[D-3'-(pyridyl)-alanine2]arginine-vasopressin (abbreviated d[D-3Pal]VP) was a potent pituitary agonist, weaker antidiuretic agonist, and weak vasoconstrictor antagonist. Another analogue, [D-3'-(pyridyl)-alanine2]arginine-vasopressin, had very weak pituitary activity but no measurable antidiuretic or vasoconstrictor activity.

Prediction of conformation of rat galanin in the presence and absence of water with the use of Monte Carlo methods and the ECEPP/3 force field.

The conformation of the 29-residue rat galanin neuropeptide was studied using the Monte Carlo with energy minimization (MCM) and electrostatically driven Monte Carlo (EDMC) methods. According to a previously elaborated procedure, the polypeptide chain was first treated in a united-residue approximation, in order to enable extensive exploration of the conformational space to be carried out (with the use of MCM). Then the low-energy united-residue conformations were converted to the all-atom representations, and EDMC simulations were carried out for the all-atom polypeptide chains, using the ECEPP/3 force field with hydration included.

Analogues of Cucurbita maxima trypsin inhibitor III (CMTI-III) with elastase inhibitory activity.

Three new CMTI-III analogues containing the Val residue in the reactive site (position 5) were synthesized by the solid-phase method. The analogues displayed an elastase inhibitory activity. It is shown that the removal of the N-terminal Arg residue and the introduction of the Gly-Pro-Gln tripeptide in the region 23-25 decreases the antielastase activity by two orders of magnitude.