摘要:

AbstractSelf‐replicating molecules stand at the very boundary of chemistry with biology. This review describes the development of synthetic structures capable of self‐replication from studies in molecular recognition. The weak intermolecular forces—hydrogen bonds and aromatic stacking interactions—that characterize interactions of nucleic acid components were designed into synthetic receptors for adenine. Covalent conjugates of these receptors with adenines gave self‐complementary structures capable of replication. The new systems feature autocatalysis, sigmoidal product growth and even mutation. General rules for the design of replicating systems are described and these suggest that the evolution of replicating molecules was an inevita

ISSN:0952-3499    

DOI:10.1002/jmr.300050302

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractX‐PLOR modelling of collagen dimers containing Gly‐Glu‐Arg in each chain has been carried out. The interaction between molecules when two Gly_Glu‐Arg are present on each chain is found to be substantially less than two times that obtained with one per chain, implying that relative tilting of two collagen molecules does not offset the disadvantages of misalignment of the interacting moieties. This implies that if multiple (Glu−‐Arg+)3interactions are important in fibril formation, their lateral separations must be large enough to insure that they act in

ISSN:0952-3499    

DOI:10.1002/jmr.300050303

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe aims of the present theoretical study of the conformations of [α]‐oligodeoxynucleotides forming triple helices with DNA duplexes are to understand the structural and energetic factors involved in [α]‐triple helix formation by means of energy minimization, and to explain the experimentally observed dependence of strand orientation on the nucleotide sequence. It is found that the energetically preferred orientation of the [α]‐oligonucleotide with respect to the homopurine strand depends on the sequence of the homopurine. homopyrimidine tracts. This is a consequence of the structural heteromorphism of base triplets in the intrinsically more stable reverse Hoogsteen hydrogen bonding configuration. Practical rules are proposed for determining the orientation of the nuclease‐resistant [α]‐oligodeoxynucleotide strand which will form the most stable

ISSN:0952-3499    

DOI:10.1002/jmr.300050304

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractWe have used the technique of multiple pin peptide synthesis to identify three major continuous epitopes in the recombinant bovine (rb) GH molecule. We have synthesized these peptides, residues 24–40, 139–152 and 179–189, as N‐terminally acetylate, C‐terminal amides and confirmed their reactivity in a standard solid‐phase ELISA. Subsequently, for epitope 139–152, we have synthesized a peptide affinity column and used this to isolate antibodies with this epitospe specificity from whole antiserum. In addition, we demonstrate that under native conditions in a liquid phase RIA, these antibodies will precipitate [125I]rbGH. Further, peptide 139–152 itself also cross‐reacts in an rbGH RIA inhibiting binding by up to 20%. Our data suggest that during the immune response to rbGH RIA in guinea‐pigs a substantial part of the B‐cell response is directed to the 139–152 region and that this part of the prot

ISSN:0952-3499    

DOI:10.1002/jmr.300050305

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe effect of pH and temperature of kinetic and thermodynamic parameters (i.e.,kon,koff,Ka, δGo, δHoand δSovalues) for the binding of the kunitz‐type trypsin inhibitor DE‐3 fromErythrina caffraseeds (ETI) to bovine β‐trypsin, bovine α‐chymotrypsin, the human tissue plasminogen activator, human α‐, β‐ and γ‐thrombin, as well as theMr33000 andMr54 000 species of the human urinary plasminogen activator (also named urokinase) has been investigated. At pH 8.0 and 21.0 °C: (i) values of the second‐order rate constant (Kon) for the proteinase: ETI complex formation vary between 8.7 × 105and 1.4 × 107/M/s; (ii) values of the dissociation rate constant (koff) for the proteinase: ETI complex destabilization range from 3.7 × 10−5to 1.4 × 104/s; and (iii) values of the association equilibrium constant (Ka) for the proteinase: ETI complexation change frombovine β‐chymotrypsin » human α‐, β‐ and γ‐thrombin ≈︁ oMr33 000 andMr54000 species of the human urinary plasminogen activator. Moreover, the serine proteinase: ETI complex formation is an endothermic, entropy‐driven, process. On increasing the pH from 5.0 to 9.0 (at 21.0 °C), the affinity of ETI for bovine β‐trypsin, the human tissue plasminogen activator and bovine α‐chymotrypsin (i.e.,Kavalues) increases, thus reflecting the acidic‐pKshift of the His57 catalytic residue from ≈︁≈︁ 7.0, in the free enzymes (pKUNL), to ≈︁5.2, in the serine proteinase: ETI complexes (pKLIG). The ETI‐binding properties have been analysed in parallel with those of related serine (pro)enzyme/macromolecular inhibitor systems. Considering the known molecular models, the observed binding behaviour of ETI is discussed in relationship to th

ISSN:0952-3499    

DOI:10.1002/jmr.300050306

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

ISSN:0952-3499    

DOI:10.1002/jmr.300050307

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

ISSN:0952-3499    

DOI:10.1002/jmr.300050301

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY