Kinetics and mechanism for the conformational transition in p-guanidinobenzoate bovine trypsinogen induced by the isoleucine-valine dipeptide

Nolte, Hans-Jürgen; Neumann, Eberhard

doi:10.1016/0301-4622(79)85014-0

Cited by 26 publications

(4 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such peptides induce the rigidification of the activation domain of trypsinogen akin to a folding process. Kinetic analysis of this reaction indicated an induced-fit mechanism by which formation of a loose complex precedes peptide integration and generation of a stable and defined species with a rate constant of 26 sK1 [21]. The formation of the binary x,-antitrypsin .…”

Section: Structural Changes O J the Complexmentioning

confidence: 98%

Structural transition of α₁‐antitrypsin by a peptide sequentially similar to β‐strand s4A

Schulze

Baumann

Knof

et al. 1990

European Journal of Biochemistry

197

153

View full text Add to dashboard Cite

Crystal structure studies have shown that cleaved and intact serpins differ essentially in the topology of P-sheet A. This is five-stranded in the intact molecules and six-stranded after cleavage by insertion of strand s4A whose C-terminus has become free [Lobermann, H., Tokuoka, R., Deisenhofer, J. is accompanied by changes in spectral properties and an increase in thermal stability. We show here that an Naacetyl-tetradecapeptide with the amino acid sequence of strand s4A, residues 345 -358 of human a,-antitrypsin, associates with intact a,-antitrypsin and forms a stoichiometric complex with properties very similar to cleaved a,-antitrypsin. Complex generation has the characteristics of a folding process. a,-Antitrypsin is a member of a superfamily of proteins, the serpins (serine protease inhibitors). Most of these proteins are serine protease inhibitors, others have lost this function and serve in extracellular body fluids as carrier proteins or as hormone precursors (for a review see [l]). The establishment of al-antitrypsin as the archetype of the serpins was strengthened by the determination of its crystallographic structure, in modified form, by Lobermann et al. [2]. The deduced structure readily explained that the proteolytically cleaved species represents an irreversible structural and functional alternative to small protease inhibitors which react reversibly (for a review see [3]). In cleaved a,-antitrypsin the Nand C-termini generated by limited proteolysis of the Met358-Ser359 bond are incorporated into P-sheets A and C, respectively. As only the structure of cleaved al-antitrypsin had been determined at the time, alternative reconstructions of the intact species were considered, but removal of strand s4A from the middle of the large P-sheet A was considered most likely [2]. The recent crystal and molecular structure of a model of an uncleaved serpin, plakalbumin, confirmed this hypothesis, and showed that cleaved and intact serpins differ essentially by the insertion of strand s4A between strands s5A and s3A into P-sheet A [4].The molecular structures of cleaved a,-antitrypsin and plakalbumin are shown for comparison in Fig. 1.Comparative measurements of CD and NMR spectra [5, 61 and heat denaturation [7] had indicated that cleaved serpins are more rigid and thermostable than the intact species, suggesting a strained conformation (S) in the intact form which relaxes (R) after limited proteolysis [2, 71. The S -+ R transition may be related to the inhibitory function, as two non-inhibitor serpins, ovalbumin and angiotensinogen, . The functional and structural implications of the S -+ R transition which involved an expansion of the P-sheet deserved further study which we pursued guided by previous observations of the trypsinogen -trypsin transition [lo]. In this system, peptides sequentially related to the N-terminus of trypsin induce the structural transition of trypsinogen to a trypsin-like state. Similarly exogenous peptides sequentially related to strand s4A induce the S -+ R transition in intact...

show abstract

Section: Structural Changes O J the Complexmentioning

confidence: 98%

Structural transition of α₁‐antitrypsin by a peptide sequentially similar to β‐strand s4A

Schulze

Baumann

Knof

et al. 1990

European Journal of Biochemistry

197

153

View full text Add to dashboard Cite

show abstract

“…A key element of this conceptual framework is that the zymogen transitions to the protease through structural changes that can also be induced by binding of specific ligands or cofactors (40). A recent extension of this view to the protease itself posits a continuum transition from zymogen-like to proteinase-like states upon ligand binding (41), based on the assumption that the protease in the free form is zymogen-like (42).…”

Section: Trypsin-like Proteases Obey Conformational Selection Notmentioning

confidence: 99%

Essential role of conformational selection in ligand binding

Vogt

Pozzi

Chen

et al. 2014

Biophysical Chemistry

View full text Add to dashboard Cite

Two competing and mutually exclusive mechanisms of ligand recognition – conformational selection and induced fit - have dominated our interpretation of ligand binding in biological macromolecules for almost six decades. Conformational selection posits the pre-existence of multiple conformations of the macromolecule from which the ligand selects the optimal one. Induced fit, on the other hand, postulates the existence of conformational rearrangements of the original conformation into an optimal one that is induced by binding of the ligand. In the former case, conformational transitions precede the binding event; in the latter, conformational changes follow the binding step. Kineticists have used a facile criterion to distinguish between the two mechanisms based on the dependence of the rate of relaxation to equilibrium, kobs, on the ligand concentration, [L]. A value of kobs decreasing hyperbolically with [L] is seen as diagnostic of conformational selection, while a value of kobs increasing hyperbolically with [L] is considered diagnostic of induced fit. However, this simple conclusion is only valid in the rather unrealistic assumption of conformational transitions being much slower than binding and dissociation events. In general, induced fit only produces values of kobs that increase with [L] but conformational selection is more versatile and is associated with values of kobs that increase, decrease with or are independent of [L]. The richer repertoire of kinetic properties of conformational selection applies to kinetic mechanisms with single or multiple saturable relaxations and explains the behavior of nearly all experimental systems reported in the literature thus far. Conformational selection is always sufficient and often necessary to account for the relaxation kinetics of ligand binding to a biological macromolecule and is therefore an essential component of any binding mechanism. On the other hand, induced fit is never necessary and only sufficient in a few cases. Therefore, the long assumed importance and preponderance of induced fit as a mechanism of ligand binding should be reconsidered.

show abstract

“…(b) The activation domain becomes ordered and the binding pocket for the ligand p-guanidobenzoate is formed in the presence of the exogenous peptide (I). Structure thermodynamics and kinetics of this system have been analysed (Huber & Bode, 1978;Nolte & Neumann, 1979). They indicate a relatively slow isomerization step (26 s-I) from a loose IT complex to the stable I T species) probably associated with the rigidification process.…”

Section: Domain Motionmentioning

confidence: 99%

Flexibility and rigidity, requirements for the function of proteins and protein pigment complexes

Huber

1987

Biochemical Society Transactions

View full text Add to dashboard Cite

Proteins may be rigid or flexible to various degrees as required for optimum function. Flexibility at the level of amino acid side-chains occurs universally and is important for binding and catalysis. Flexibility of large parts of a protein which rearrange or move are particularly interesting and will be discussed here. We differentiate between certain categories of large-scale flexibility although the boundaries between them are diffuse: flexibility of peptide segments, domain motions and order-disorder transitions of spatially contigous regions. The domains may be flexibly linked to allow rather unrestricted motion or the motion may be constrained to certain modes. The polypeptide segments linking the domains show characteristic structural features. The various categories of flexibility will be illustrated with the following examples. (a) Small protein proteinase inhibitors which are rather rigid molecules which provide binding surfaces complementary to their cognate proteases, but also show limited segmental flexibility and adaptation. (b) Large plasma inhibitors which exhibit large conformational changes upon interaction with proteases probably for regulatory purposes. (c) Pancreatic serine proteases which employ a disorder-order transition of their activation domain as a means to regulate enzymic activity. (d) Immunoglobulins in which rather unrestricted and also hinged domain motions occur in different parts of the molecule probably to allow binding to antigens in different arrangements. (e) Citrate synthase which adopts open and closed forms by a hinged domain motion to bind substrates and release products and to perform the catalytic condensation reaction, respectively. (f) The bifunctional multienzyme complex riboflavin synthase in which two enzymes (alpha and beta) catalyse two consecutive enzymic reactions. The beta-subunits form a shell, in which the alpha-subunits are enclosed. Diffusional motion of the catalytic intermediates is therefore restricted. In addition, segmental rearrangement occurs in the assembly of the beta-subunit. In contrast, rigidity is the dominant impression provided by the structures of the light harvesting complexes and the reaction centres involved the photosynthetic light reactions. These are large protein complexes in which the proteins serve as matrices to hold the pigments in the appropriate conformation and relative arrangement. Since motion would contribute to deactivation of the photo-excited states of the pigments and diminish the efficiency of light energy and electron transfer, a functional role for rigidity is easy to rationalize for these proteins.

show abstract

Kinetics and mechanism for the conformational transition in p-guanidinobenzoate bovine trypsinogen induced by the isoleucine-valine dipeptide

Cited by 26 publications

References 9 publications

Structural transition of α₁‐antitrypsin by a peptide sequentially similar to β‐strand s4A

Structural transition of α₁‐antitrypsin by a peptide sequentially similar to β‐strand s4A

Essential role of conformational selection in ligand binding

Flexibility and rigidity, requirements for the function of proteins and protein pigment complexes

Contact Info

Product

Resources

About

Kinetics and mechanism for the conformational transition in p-guanidinobenzoate bovine trypsinogen induced by the isoleucine-valine dipeptide

Cited by 26 publications

References 9 publications

Structural transition of α1‐antitrypsin by a peptide sequentially similar to β‐strand s4A

Structural transition of α1‐antitrypsin by a peptide sequentially similar to β‐strand s4A

Essential role of conformational selection in ligand binding

Flexibility and rigidity, requirements for the function of proteins and protein pigment complexes

Contact Info

Product

Resources

About

Structural transition of α₁‐antitrypsin by a peptide sequentially similar to β‐strand s4A

Structural transition of α₁‐antitrypsin by a peptide sequentially similar to β‐strand s4A