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Protein and Peptide Letters, Vol. 6, No. 3, 1996

Contents

Short Review

Tolerance of Protein Structures to the Changes of Amino Acid Sequences and Their Interactions. The Nature of the Folding Code. Pp. 115-130.
Alexander P. Demchenko and Vladimir A. Chinarov
[Abstract]

Regular Papers

De Novo Design and CD Studies of Model b-Sheet Peptides. Pp. 131-136.
Yinlin Sha, Yinling Li, Qi Wang, Keqiatig Fan, Dongsheng Liu, Luhua Lai and Youqi Tang
[Abstract]

CD Evidence of a Peptide Ongoing a/b/Random Transition in Different Solutions. Pp. 137-140.
Yinlin Sha, Yinling Li, Qi Wang, Keqiang Fan, Dongsheng Liu, Luhua Lai and Youqi Tang
[Abstract]

Nanoparticle Formation of Self-Assembling Two-a-Helix Peptide Induced by Heme-Binding. Pp. 141-144.
Ikuo Obataya, Seiji Sakamoto, Akihiko Ueno and Hisakazu Mihara
[Abstract]

Flexible Synthesis of Symmetric and Non-Symmetric HIV-I Protease Inhibitors Based on ALL-S-Diaminodiol Isosteres. Pp. 145-148.
Alessandro Tossi, Nikolinka Antcheva, Fabio Benedetti, Stefano Norbedo, Stanislav Miertus and Domenico Romeo
[Abstract]

19F NMR Study of the Binding of Fluorinated Diethylstibestrol to the Human Estrogen Receptor. Pp. 149-154.
Matthew C. Skeels, Branka Salopek Sondi and Linda A. Luck
[Abstract]

Microwave Exposure Effect on a Thermophilic Alcohol Dehydrogenase. Pp. 155-162.
La Cara, F., D'Auria, S., Scarfi, M.R., Zeni, 0., Massa, R., d'Ambrosio, G., Franceschetti, G., De Rosa, M. and Rossi, M.
[Abstract]

Specificity of the Vatairea macrocarpa Lectin Towards Glycans Exhibiting Exposed Gal/GalNAc Residues. Pp. 163-172.
Marcio V. Ramos, Benildo S. Cavada, Juan J. Calvete, Alexandre H. Sampaio, Anne M. Mazard, Anick Barre, Thalles B. Grangeiro, Beatriz T. Freitas, Katia B. Leite and Pierre Rouge
[Abstract]

Inactivated Actin, An Aggregate Comprised of Partially-Folded Monomers, Has an Overall Native-Like Packing Density. Pp. 173-178.
Irma M. Kuznetsova, Konstantin K. Turoverov and Vladimir N. Uversky
[Abstract]

Autoantibodies with Amylolytic Activity. Pp. 179-184.
Andrew N. Savel'ev, Elena V. Eneyskaya, Konstantin A. Shabalin, Michael V. Filatov and Kirill N. Neustroev
[Abstract]


Abstracts

[Back to top] Tolerance of Protein Structures to the Changes of Amino Acid Sequences and Their Interactions. The Nature of the Folding Code. Alexander P. Demchenko and Vladimir A. Chinarov.
Nascent disordered polypeptide chains fold into unique three-dimensional protein structures spontaneously. The information inherent in amino acid sequences, which determines the resultant protein conformation, is called the "folding code". Numerous examples demonstrate that the folding code is degenerate and allows a variety of artificial changes in amino acid residues and their interactions. In this aspect, the meaning and the mechanisms of realization of folding code are discussed.

[Back to top] De Novo Design and CD Studies of Model b-Sheet Peptides. Yinlin Sha, Yinling Li, Qi Wang, Keqiatig Fan, Dongsheng Liu, Luhua Lai and Youqi Tang.
Two nine-residue peptide sequences (al, a2) with [(Hb-Hb-Hp-Hp)-Hb-(Hp-Hp-Rb-Hb)] (Hb, hydrophobic residue, Hp, hydrophilic residue) pattern were synthesized by solid phase peptide synthesis protocol and purified by RP-HPLC. The CD spectrum of al in water shows a positive near 196.5nm and a negative at ca 216.5nm, which have been considered as the characteristics of b-sheet. The characteristic of a2 curve, a negative near 213nm and a shoulder at 199nm has been postulated as the contribution from b-sheet mixed with random coil. The peptide al is also characterized by chemical and thermal denaturations.

[Back to top] CD Evidence of a Peptide Ongoing a/b/Random Transition in Different Solutions. Yinlin Sha, Yinling Li, Qi Wang, Keqiang Fan, Dongsheng Liu, Luhua Lai and Youqi Tang.
Conformational transition is a very interesting topic of solution of protein aggregation and amyloid formation. The design, synthesis, purification and conformational studies of a nine-residue peptide (LLEELKEVL, name al) in water have been discussed recently [1]. Here we report the confirmational transitions of al in different solutions. In water or in TFE the CD spectrum shows a maximum at 198nm and a minimum at 217nm, a typical characteristic of b-sheet. A negative maximum at ca. I 98nm is observed in PBS (pH 7.02), which have been concluded as the characteristics of random coil. With the titration of SDS solution (5%-10%), the negative near 207 and 222nm are enhanced, which means the helix component increases. The thermal denaturation studies of al in TFE or in SDS indicate the oligomerization of the peptide.

[Back to top] Nanoparticle Formation of Self-Assembling Two-a-Helix Peptide Induced by Heme-Binding. Ikuo Obataya, Seiji Sakamoto, Akihiko Ueno and Hisakazu Mihara.
A designed two-a-helix peptide H6-2a bound effectively Fe(III)-mesoporphyrin (heme) and the heme-binding simultaneously induced the formation of nanoparticles. Thus, new self-assembling system of peptide with heme was accomplished.

[Back to top] Flexible Synthesis of Symmetric and Non-Symmetric HIV-I Protease Inhibitors Based on ALL-S-Diaminodiol Isosteres. Alessandro Tossi, Nikolinka Antcheva, Fabio Benedetti, Stefano Norbedo, Stanislav Miertus and Domenico Romeo.
C2 symmetric and non-symmetric pseudopeptide inhibitors of HIV-1 protease, containing S,S,S,S,-diaminodiol isostere have been obtained by a synthetic strategy designed to couple a high degree of stereochemical control with complete flexibility in the choice of residues in the central core and flanking chains. Using this approach, inhibitors with 1C50 values in the low nanomolar range were assembled from readily available aminoacids and carboxylic acids, chosen with the aid of molecular modelling.

[Back to top] 19F NMR Study of the Binding of Fluorinated Diethylstibestrol to the Human Estrogen Receptor. Matthew C. Skeels, Branka Salopek Sondi and Linda A. Luck.
In this paper we report the binding of hexafluorodiethylstibestrol to two constructs of the recombinant hormone-binding domain of the human estrogen receptor produced in E. coli. Our fluorine NMR studies have shown the protein to selectively bind the E-isomer and the NMR signals show protein-induced shifts.

[Back to top] Microwave Exposure Effect on a Thermophilic Alcohol Dehydrogenase. La Cara, F., D'Auria, S., Scarfi, M.R., Zeni, 0., Massa, R., d'Ambrosio, G., Franceschetti, G., De Rosa, M. and Rossi, M.
It has been studied the effect of microwave irradiation on the thermostable alcohol dehydrogenase isolated from the Archaeon Sulfolobus solfataricus in order to discriminate between thermal and non-thermal effects of such non-ionizing radiations on protein's features. The results indicate a non-thermal effect of microwave on the structural and functional properties of the enzyme as well as the dependence of the enzyme stability from the protein concentration.

[Back to top] Specificity of the Vatairea macrocarpa Lectin Towards Glycans Exhibiting Exposed Gal/GalNAc Residues. Marcio V. Ramos, Benildo S. Cavada, Juan J. Calvete, Alexandre H. Sampaio, Anne M. Mazard, Anick Barre, Thalles B. Grangeiro, Beatriz T. Freitas, Katia B. Leite and Pierre Rouge.
The binding specificity of the lectin from Vatairea macrocarpa, a legume from tribe Dalbergieae, was investigated by surface plasmon resonance measurements and molecular modelling and docking. The lectin is a Gal/GalNac-specific protein which readily interacts with both N- and O-linked glycans. It resembles other legume lectins from the closely related tribe Sophoreae characterized so far. Its specific interaction with glycoproteins should allow its use as a tool for both the isolation and characterization of various N- and O- linked glycoconjugates.

[Back to top] Inactivated Actin, An Aggregate Comprised of Partially-Folded Monomers, Has an Overall Native-Like Packing Density. Irma M. Kuznetsova, Konstantin K. Turoverov and Vladimir N. Uversky.
The packing density of inactivated actin was analyzed by comparison of "apparent" molecular mass, Mapp, (measured by gel-filtration column, calibrated by native proteins with known molecular masses) with the "true" value of this parameter, Mtrue (calculated from the Stokes radius, RS, and sedimentation constant, s). The determined values were comparable reflecting the fact that packing density of the inactivated actin is rather close to that of native proteins.

[Back to top] Autoantibodies with Amylolytic Activity. Andrew N. Savel'ev, Elena V. Eneyskaya, Konstantin A. Shabalin, Michael V. Filatov and Kirill N. Neustroev.
Hydrolytic activity toward maltooligosaccharides was found in the human IgG fraction purified by affinity chromatography with protein G-Sepharose followed by ion-exchange and gel-permeation chromatography. The IgG Fab was shown to retain the amylolytic activity. Amylolytic activity of the IgG fraction from pregnant donors was 50 fold higher than from normal donors. Increased amylolytic activity of the IgG fraction was detected in blood from oncological donors.