ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02358.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The protected nonapeptide, Z‐Asn‐Glu(OBzl)‐Glu(OBzl)‐Gly‐Leu‐Phe‐Gly‐Gly‐ Arg(NO2)OMe, corresponding to the amino acid sequence present in fibrinopeptide‐B of green monkey, has been synthesised by c

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02359.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

A protected decapeptide corresponding to a section found in the last half of the protein chain of rubredoxin has been prepared by standard peptide methods.

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02360.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The solid phase synthesis of pentagastrin (I), Z‐Trp‐Met‐Gly‐Phe‐NH2(II), pGlu‐Gln‐ Ala‐NH2(III) and pGlu‐Asn‐Ala‐NH2(IV) by a modified technique is described. These peptide amides are obtained by the direct ammonolysis of the corresponding peptide resins. For the synthesis of III and IV, N‐ethoxycarbonyl‐2‐ethoxy‐l,2‐dihydroquinoline (EEDQ) was used as the coupling agent. No nitrite formation

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02361.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The effects of combining two different alcohols on the transition temperature of ribonuclease were investigated.It appears that at 60°C the combined effects on the transition temperature of ribonuclease of two different alcohols are equal to the algebraic sum of the effects of each individual alcohol. This holds true for a combination of two monohydric alcohols, two polyhydric alcohols and a combination of a monohydric and a polyhydric alcohol.At lower temperatures only the effects of the combinations of two polyhydric alcohols show additivity. The combined effect of a polyvalent alcohol and a monovalent alcohol at low temperature is surprisingly higher than the algebraic sum of the effects of the individual alcohols.The polyhydric alcohol enhances the hydrophobic effect of the monovalent alcohol for temperatures up to 50°C. Obviously the polyhydric alcohol perturbs the water structure at these low temperatures, which leads to the intensifying of the interhydrophobic interactions.Furthermore, the combined effect of two different monovalent alcohols with different hydrophobic effects does not show additivity at low temperatures. The single (OH) group of the weakest hydrophobic alcohol enhances the hydrophobic effect of the potentially strongest hydrophobic alcoho

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02362.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The development of the eye lens in the prenatal phase is accompanied by a gradual change in the polypeptide composition of α‐crystallin. As the lens matures from that of a 6‐week‐old embryo to that of a new‐born calf, there is a successive appearance of different polypeptides although two obviously principal polypeptides, A2and B2, are present at every stage of development. The youngest embryonic lenses studied contain four polypeptides. Two of them differ from the well‐known polypeptides as found in cortical bovine α

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02363.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The optimal number of differences between sequences for phylogenetic studies is derived, and the developed theory is used to show that a sequenced peptide assumed to be duck proinsulin C‐peptide had the expected differences from the mammalian C‐peptides. The theory is used to separate the guinea pig insulin from other insulins, indicating that the pressure of selection on guinea pig insulin has been significantly lower than that on other insulins. Finally, calculation of the half‐life of a protein as a measure of the pressure of selection rather than the evolutionary rate constant is pro

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02364.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

The physical state of bovine serum albumin in LiCl solutions at the pH near isoelectric point and room temperature has been studied with intrinsic viscosity, optical rotatory dispersion, circular dichroism and ultraviolet absorption difference spectra. The results indicate that the effects of Li+ take place in two processes. 1. At the concentration of LiCl below 4.0 M, only the general electrostatic effect occurs. There is no conformational change in the protein. 2. At the concentration of LiCl above 4.0 M, a specific effect of the Li+ occurs in which both the secondary and tertiary structures of the protein change. In addition, the protein molecules aggregate. In correspondence with the two processes, two different possible mechanisms are discussed.

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02365.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

A model of albumin is proposed which accounts for the behaviour of bovine serum albumin during proteolytic hydrolysis by several enzymes. This model is tested and confirmed by conformational studies on large fragments of albumin at acid and neutral pH by means of optical rotation and hydrogen ion titration. The isolation of some fragments is described. It is suggested that BSA is a compact molecule at neutral pH, while in the F‐configuration it is composed of a compact NH2‐terminal moiety, and a COOH‐terminal part with a loose structure, which is very susceptible to proteolytic cleavage. The N‐F transition can be interpreted as an isomerization of the NH2‐terminal moiety, without loss of helix content, and an unfolding of the COOH‐terminal part in a cooperative process. Some parallelism between acid and neutral transition is d

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02366.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

A nonapeptide, Arg‐Glu‐Leu‐Glu‐Asp‐Gly‐Thr‐Pro‐Arg, corresponding to the 123–131 sequence of bovine pituitary growth hormone, was prepared by a modified solid phase synthesis. To avoid an acid‐ or base‐catalysed rearrangement at the Asp‐Gly bond, which gives rise to an aspartimide‐containing peptide, a new combination of protecting groups was introduced. The 2‐(4‐biphenylyl)‐2‐propyloxycarbonyl group was used for Nα‐protection, a t‐butyl ester for the β‐carboxyl of aspartic acid, and a p‐alkoxybenzyl alcohol ester for the anchoring bond to the resin support. The nonapeptide showed growth hormone activity in the hypophysectomized rat tibia epiphyseal width test, but was inactive in the

ISSN:0367-8377    

DOI:10.1111/j.1399-3011.1974.tb02367.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY