摘要:

It was found that the first‐order deamidation half‐times of the peptides Gly‐Asp‐Asn‐Ile‐Gly, Gly‐Glu‐Asn‐Val‐Gly, Gly‐Arg‐Gln‐Gly‐Gly, and Gly‐Ile‐Gln‐Gly‐Gly in pH 7.4, 1=0.2, 37°C phosphate buffer are 75, 145, 305, and 735 days respectively. These peptides are analogous to the amide parts of histone IV. The findings are discussed with respect to the possible biological implications of

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02385.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The most common ordered peptide conformations, i.e. right‐handed α‐helix, β‐structure, and triple‐helical collagen‐type conformation, are all supported by ethylene glycol, as determined by circul

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02386.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Horseradish peroxidase(hydrogen peroxide oxidoreductase[1.11.1.7])has been cross‐linked in methylene chloride using N,N'‐carbonyldiimidazole to produce a water insoluble preparation which retains enzymatic activity. Relative to native enzyme, which was treated with methylene chloride but not N,N'‐carbonyldiimidazole, the cross‐linked product displayed significant stability toward denaturation in aqueous mixtures of ethanol, methanol, and 1,4‐dioxane. The cross‐linked product showed a a marked stability toward thermal denaturation relative to the native protein. Applications of the catalyst in chemical reactors for the preparation of synthetic quinones ar

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02387.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The heat denaturation of lysozyme has been studied by proton magnetic resonance spectroscopy at 220 MHz in water at pH 2.8. At 20°C a broad resonance is observed at 6.8δ due to the arginine NH2resonances, which becomes a well defined triple resonance at 40°C, without any change in the rest of the spectrum. This sharpening of the arginine NH2resonances is due to their increased mobilities and/or some normalisation of their chemical shifts. It is proposed that the surface structure of lysozyme is loosened at 40°C, without any change in the hydrophobic core and this is considered to be an intermediate phase in its heat denaturation. The heat denatured product at 80°C in D2O retains some noncovalent interactions, since further treatment with guanidine deuterochloride or mercaptoethanol causes sharpening of the aromatic region of the spec

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02388.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The solid‐phase synthesis of α‐melanotropin hydrazide, a new analog of α‐MSH, is described. Cleavage of the partially protected peptide from the solid support was accomplished with hydrazine in dimethylformamide. The protecting groups were removed with sodium in liquid ammonia and the product was purified by chromatography on carboxymethylcellulose to give a highly purified and melanotropically active trideca

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02389.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Amino acid containing polymers were synthesized by heating mixtures of aspartic acid, glutamic acid, glycine, alanine, valine, leucine, isoleucine, and proline in the absence of water at temperatures of 180° to 190°C for several hours. The resulting product was fractionated by dialysis, gel filtration, and chromatography and electrophoresis on paper. The larger polymers were found to be rich in aspartic acid and poor in proline, while the smaller molecules were rich in glutamic acid and contained proline as a significant constituent. The N‐terminal positions are believed to be occupied largely by pyroglutamic acid, while the C‐terminal positions are comprised exclusively of aliphatic amino acids. Aspartic acid and glutamic acid were individually treated to the polymerization conditions. Little reaction of aspartic acid was observed, but glutamic acid formed a melt and upon cooling a glass. Investigation of this product indicated it to be a highly hydrogen bonded system of pyroglutamic and glutamic acids. The model system of glutamic acid and decylamine produced under polymerization conditions, the decylamide of pyroglutamic acid. The accumulated results suggest a model for thermal polymeriz

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02390.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The octapeptide, Ser‐Ser‐Thr‐His‐Pro‐Val‐Phe‐His, corresponding to the first eight amino‐terminal residues in the sequence of mouse nerve growth factor, has been synthesized by the manual solid‐phase technique. After cleavage of the peptide material from the peptide‐resin by HF, extensive purification produced the expected product in good yield(27% of potential starting sites; 58% of the released product).The peptide was characterized by chromatographic techniques, sequence analysis, enzymatic digestion, CD and ORD spectral analyses, and biological and pharmacological assays. Detailed analysis of the reaction by‐products, isolated during the purification of the principal product, provided technical information regarding possible synthetic side reactions and further evidence for dynamic solvation of the polymer matrix as a dominant factor in

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02391.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

For a better understanding of the role played by glut amine 11 either in the catalytic function of ribonuclease A or in the S‐peptide/S‐protein association process the following S‐peptide analogs have been synthesized: [Orn10,Leu11]‐and[Orn10,Lys11]‐S peptide.The S‐protein activating ability of the two synthetic S‐peptide analogs was tested, before and after guanidination, by exploring their capacity to generate ribonuclease activity, against RNA as substrate, when recombined w

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02392.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The S‐protein activating ability of[Orn10,Glu11]‐, [Orn10,Leu11]‐and[Orn10,Lys11]‐S‐ peptide was tested, before and after guanidination, by exploring their capacity to regenerate ribonuclease activity when recombined with S‐protein. The kinetic parametersKmandk2of the resulting modified enzymes were also calculated using C>p and CpC as the substrates. In agreement with previous observations the results obtained indicate that the carboxamide function in position 11 is not essential for biological activity, but contributes by optimizing the RNase A catalyt

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02393.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The Vmaxand Kmvalues for the hydrolysis of Nα‐tosyl‐L‐arginine methyl ester, Nα‐benzoyl‐L‐arginine methyl ester, N‐acetyl‐L‐tryosine ethyl ester and N‐benzoyl‐L‐tyrosine ethyl ester by alkalinemesentericopeptidasewere determined. It is concluded that there is a similarity in the esterolytic properties ofmesentericopeptidaseand the subtilisins.Mesentericopeptidaseis nearer to subtilisins Novo andAmylosacchariticusthan to subtilisin Carlsberg. The Kmvalues for the hydrolysis of Na‐tosyl‐L‐arginine methyl ester by alkalinemesentericopeptidasewere approximately constant over the pH range 5.5 to 8.0. A pK of 6.6 at 37° C was determined from the sigmoid pH‐velocity profile for the hydrolysis of this substrate. The data indicate that there is an imidazole group in the active site of the alkaline protease fromBac. mesentericusthat must be non‐protonated for hydrolysis to take place. The amino acid compositions ofmesentericopeptidaseand subtilisinAmylosacchariticusare almost identical, but there are differences in the mechanism of action of these two enzymes. The conclusion is drawn that alkalinemesentericopeptidasebelongs to the subtilisin BPN'‐group of alkaline proteases according t

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02394.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY