Human fibrinogen was illuminated in the presence of methylene blue. The resulting photooxidized fibrinogen was devoid of polymerization activity and thrombin-induced coagulability. The initial rate of the thrombin catalysed release of fibrinopeptides from photooxidized fibrinogen was normal. It was shown that illumination of photooxidized fibrinogen and photooxidized fragment N-DSK caused the modification of histidine residues. Tryptophan residues were also modified. When fibrinogen was photooxidized immediately after the addition of thrombin, the capacity to polymerize was lost. The inhibition of polymerization was less marked when oxidation was initiated at the time when polymerization began or thereafter. Photooxidized fibrinogen acts as an inhibitor of the polymerization of fibrin monomers. Photooxidized fibrinogen has affinity for thrombin-activated fibrinogen-Sepharose and thrombin-activated fragment N-DSK-Sepharose. When the former conjugate is illuminated in the presence of methylene blue its affinity for fibrinogen is decreased. It is concluded that the fragment N-DSK domain of fibrinogen is affected by photooxidation.

It has been observed that proline residues often initiate overlaps during sequenator analysis. The cause has been shown to be an abnormally slow cleavage reaction. The kinetics of the cleavage reaction has been studied and found to obey pseudo-first-order kinetics. There are considerable differences in reaction rates depending on the position of proline in the sequence, as demonstrated for the four prolines in the N-terminal section of the H2B histone from chicken.

FEBS LettersVolume 10, Issue 5 p. 349-351 Full-length articleFree Access Scorpion neurotoxins: A family of homologous proteins H. Rochat, H. Rochat Laboratoire de Biochimie Médicale, Faculté de Médecine, 13-Marseille, France St. Vincent's School of Medical Research, Melbourne, AustraliaSearch for more papers by this authorC. Rochat, C. Rochat Laboratoire de Biochimie Médicale, Faculté de Médecine, 13-Marseille, France St. Vincent's School of Medical Research, Melbourne, AustraliaSearch for more papers by this authorC. Kupeyan, C. Kupeyan Laboratoire de Biochimie Médicale, Faculté de Médecine, 13-Marseille, France St. Vincent's School of Medical Research, Melbourne, AustraliaSearch for more papers by this authorF. Miranda, F. Miranda Laboratoire de Biochimie Médicale, Faculté de Médecine, 13-Marseille, France St. Vincent's School of Medical Research, Melbourne, AustraliaSearch for more papers by this authorS. Lissitzky, S. Lissitzky Laboratoire de Biochimie Médicale, Faculté de Médecine, 13-Marseille, France St. Vincent's School of Medical Research, Melbourne, AustraliaSearch for more papers by this authorP. Edman, P. Edman Laboratoire de Biochimie Médicale, Faculté de Médecine, 13-Marseille, France St. Vincent's School of Medical Research, Melbourne, AustraliaSearch for more papers by this author H. Rochat, H. Rochat Laboratoire de Biochimie Médicale, Faculté de Médecine, 13-Marseille, France St. Vincent's School of Medical Research, Melbourne, AustraliaSearch for more papers by this authorC. Rochat, C. Rochat Laboratoire de Biochimie Médicale, Faculté de Médecine, 13-Marseille, France St. Vincent's School of Medical Research, Melbourne, AustraliaSearch for more papers by this authorC. Kupeyan, C. Kupeyan Laboratoire de Biochimie Médicale, Faculté de Médecine, 13-Marseille, France St. Vincent's School of Medical Research, Melbourne, AustraliaSearch for more papers by this authorF. Miranda, F. Miranda Laboratoire de Biochimie Médicale, Faculté de Médecine, 13-Marseille, France St. Vincent's School of Medical Research, Melbourne, AustraliaSearch for more papers by this authorS. Lissitzky, S. Lissitzky Laboratoire de Biochimie Médicale, Faculté de Médecine, 13-Marseille, France St. Vincent's School of Medical Research, Melbourne, AustraliaSearch for more papers by this authorP. Edman, P. Edman Laboratoire de Biochimie Médicale, Faculté de Médecine, 13-Marseille, France St. Vincent's School of Medical Research, Melbourne, AustraliaSearch for more papers by this author First published: October 01, 1970 https://doi.org/10.1016/0014-5793(70)80470-7Citations: 87AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume10, Issue5October 01, 1970Pages 349-351 ReferencesRelatedInformation

Anyone entering the field of protein structure determination will be faced with a bewildering choice between techniques for sequence determination. To sort the useful from the less useful, or even unworkable, could be difficult indeed. However, well-trodden tracks exist. These will be described here in some detail together with traps not to be fallen into, sidetracks not to be taken, and spooks not to be feared.

The reaction of cyanogen bromide with peptides and proteins in anhydrous formic acid has been studied. Cleavage of the side chain of methionine to yield methyl thiocyanate was quantitative for six of the seven compounds in the study. A cyclic imidate, proposed by earlier workers as an intermediate in the cleavage of the peptide chain, has now been identified.

A technique is described to facilitate the identification of cysteine residues in sequence determination by the phenylisothiocyanate degradation procedure. Cysteine residues are identified as phenylthiohydantoin derivatives of S-methylcysteine, S-ethylcysteine, or S-allylcysteine. The preparation, properties, and identification by thin-layer chromatography of these derivatives are described. Procedures for S-methylation, S-ethylation, and S-allylation of cysteine residues are given, and the application to the Toxin II of Androctonus australis is described.

Our study investigates the effect of fetal and adult soluble fibrin (SF), fetal and adult fibrinogen Aα- and γ-chains, as well as adult CNBr-fibrinogen fragments on tissue-type plasminogen activator (t-PA)-catalyzed plasminogen activation of both fetal and adult Glu-plasminogen types 1 and 2. In addition, we determined carbohydrate sequences of fetal and adult Bβ- and γ-chains by mass spectrometric analysis. In the absence of an effector, no substantial differences in the rate of plasmin formation could be seen between the fetal and adult plasminogen types. In the presence of an effector, both fetal Glu-plasminogen types revealed lower values for kcat app than the respective adult types. No differences could be seen in the values for Km app. The resulting differences in catalytic efficiencies between the fetal and adult plasminogen types were much less than previously reported. No differences could be seen between fetal and adult effectors in stimulating t-PA-catalyzed plasminogen activation. Detailed analyses of the activation kinetics revealed a longer initial phase of slow plasmin formation of both fetal Glu-plasminogen types compared to their respective adult types, indicating a slower plasmin-induced modification of CNBr-fibrinogen fragments or SF by fetal plasmin. Mass spectrometric analysis of the N-glycans present on adult and fetal Bβ- and γ-fibrinogen chains showed the presence of a major monosialylated biantennary structure with lesser amounts of the disialylated form. In contrast to previous data, we conclude that catalytic efficiency of t-PA-catalyzed plasminogen activation in neonates is only slightly lower than in adults.

FEBS LettersVolume 2, Issue 1 p. 33-35 Full-length articleFree Access Amino acid sequence at the N-terminal end of a cold agglutinin Kappa chain P. Edman, P. Edman St. Vincent's School of Medical Research, Melbourne, Victoria 3065, Australia M.R.C. Group for Research in Haemolytic Mechanisms, Royal Postgraduate Medical School, London, W. 12, EnglandSearch for more papers by this authorA.G. Cooper, A.G. Cooper St. Vincent's School of Medical Research, Melbourne, Victoria 3065, Australia M.R.C. Group for Research in Haemolytic Mechanisms, Royal Postgraduate Medical School, London, W. 12, EnglandSearch for more papers by this author P. Edman, P. Edman St. Vincent's School of Medical Research, Melbourne, Victoria 3065, Australia M.R.C. Group for Research in Haemolytic Mechanisms, Royal Postgraduate Medical School, London, W. 12, EnglandSearch for more papers by this authorA.G. Cooper, A.G. Cooper St. Vincent's School of Medical Research, Melbourne, Victoria 3065, Australia M.R.C. Group for Research in Haemolytic Mechanisms, Royal Postgraduate Medical School, London, W. 12, EnglandSearch for more papers by this author First published: October 1968 https://doi.org/10.1016/0014-5793(68)80093-6Citations: 22AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume2, Issue1October 1968Pages 33-35 ReferencesRelatedInformation

The protein sequenator is an instrument for the automatic determination of amino acid sequences in proteins and peptides. It operates on the principle of the phenylisothiocyanate degradation scheme. The automated process embraces the formation of the phenylthiocarbamyl derivative of the protein and the splitting off of the N‐terminal amino acid as thiazolinone. The degradation proceeds at a rate of 15.4 cycles in 24 hours and with a yield in the individual cycle in excess of 98%. The material requirements are approximately 0.25 μmoles of protein. The thiazolinones are converted to the corresponding phenylthiohydantoins in a separate operation, and the latter identified by thin layer chromatography. The process has been applied to the whole molecule of apomyoglobin from the humpback whale, and it has been possible to establish the sequence of the first 60 amino acids from the N‐terminal end.

THE general structural features of the various types of immunoglobulins are known and the details of the primary structure are gradually being filled in. A characteristic feature of the immune response, however, is its specificity and here the data have not been sufficient to reveal the structural basis of the specificity and even less the underlying genetic mechanism. The aim of the present investigation was to throw more light on this problem, and to this end we have determined the NH2-terminal sequences of a large number of χ-chains and made a comparison of their structures.

1.1. Four different fibrinopeptides, A, AP, Y and B, have been isolated from human fibrinogen by means of chromatography and precipitation procedures.2.2. The amino acid sequence has been determined with the phenylisothiocyanate degradation method and by means of fragmentation with proteolytic enzymes and partial acid hydrolysis. The A-, AP- and Y-peptides are similar in structure, the AP-peptide being an A-peptide phosphorylated at the serine residue in Position 3 from the N-terminal end and the Y-peptide being one amino acid residue shorter than the A-peptide from the N-terminal end. The B-peptide has been found to have pyroglutamic acid as N-terminal residue.3.3. The phosphorus in human fibrinogen is partly bound to an AP-peptide and partly to other structures of the fibrinogen molecule.4.4. On basis of the results the structure of human fibrinogen and the specificity of thrombin is discussed.

In an attempt to extend the application of the phenylisothiocyanate degradation of peptides it was found necessary to study the kinetics of the conversion of phenylthiocarbamyl amino acids into phenylthiohydantoins. The conversion was found to obey first-order kinetics and to be catalyzed by hydrogen ions. A set of conditions with regard to time, hydrogen ion concentration and temperature was found, which allowed the quantitative or near quantitative conversion of all phenylthiocarbamyl amino acids into phenylthiohydantoins with the only exception of the phenylthiohydantoin of serine, which was returned in a yield of 20%.

A study has been made of the N-terminal amino acid pattern of human plasma proteins under normal and pathological conditions. The normal pattern shows the following N-terminal amino acids in order of diminishing quantities: aspartic acid, glutamic acid, valine, alanine, tyrosine, leucines, and glycine. In healthy individuals this pattern is qualitatively stable with moderate quantitative differences between individuals. On the other hand radical quantitative changes in the pattern have been observed under pathological conditions.

Annals of the New York Academy of SciencesVolume 88, Issue 3 p. 602-610 PHENYLTHIOHYDANTOINS IN PROTEIN ANALYSIS Pehr Edman, Pehr Edman St. Vincent's School of Medical Research, Melbourne, AustraliaSearch for more papers by this author Pehr Edman, Pehr Edman St. Vincent's School of Medical Research, Melbourne, AustraliaSearch for more papers by this author First published: August 1960 https://doi.org/10.1111/j.1749-6632.1960.tb20056.xCitations: 129AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat References EDMAN, P. 1949. Arch. Biochem. 22: 475. EDMAN, P. 1950. Acta Chem. Scand. 4: 283. EDMAN, P. 1953. Acta Chem. Scand. 7: 700. EDMAN, P. 1956. Acta Chem. Scand. 10: 761. EDMAN, P. & J. SJÖQUIST. 1956. Acta Chem. Scand. 10: 1507. HIRS, C. H. W. 1956. J. Biol. Chem. 219: 611. JOLLÈS, P., J. JOLLÈS-THAUREAUX & C. FROMAGEOT. 1958. Symposium on Protein Structure.: 277. A. Neuberger, Ed. Methuen. London , England . PIERCE, J. G. 1955. J. Am. Chem. Soc. 77: 184. SCHRAMM, G., J. W. SCHNEIDER & A. ANDERER. 1956. Z. Naturforsch. 11b: 12. SJÖQUIST, J. 1953. Acta Chem. Scand. 7: 447. SJÖQUIST, J. 1957a. Arkiv. Kemi. 11: 129. SJÖQUIST, J. 1957b. Arkiv. Kemi. 11: 151. STEIN, W. H. & S. MOORE. 1949. J. Biol. Chem. 178: 79. VAN VUNAKIS, H. & E. BRAND. 1951. Abstracts of Papers, 119th Meeting Am. Chem. Soc. 28c. Citing Literature Volume88, Issue3Amino Acids, Peptides, and ProteinsAugust 1960Pages 602-610 ReferencesRelatedInformation

The Hippo pathway was initially discovered in Drosophila melanogaster as a key regulator of tissue growth. It is an evolutionarily conserved signaling cascade regulating numerous biological processes, including cell growth and fate decision, organ size ...Read More

IN the course of a study of the N,O-acyl shift at the hydroxyamino-acid residues of proteins (N,O-peptidyl shift) we observed that under certain conditions lysozyme was reversibly inactivated in a way suggestive of a direct dependence on the reversible N,O-peptidyl shift. In earlier work1 on this rearrangement in proteins, concentrated mineral acids were employed, and concomitant, irreversible processes then make it difficult to observe any connexion between the N,O-peptidyl shift and the biological activity. However, a search for milder conditions has revealed that the reaction also takes place in formic acid at ordinary temperature, and apparently without other changes2.