Subsites of Trypsin Active Site Favor Catalysis or Substrate Binding

Marana, Sandro R.; Lopes, Adriana Rios; Juliano, Luiz; Juliano, María A.; Ferreira, Clélia; Terra, Walter R.

doi:10.1006/bbrc.2001.6172

Cited by 20 publications

(59 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Plots of DG T z versus DG s are straight lines for all insect chymotrypsin subsites, as exemplified in Fig. 2 and previously shown for insect trypsins (Marana et al, 2002;Lopes et al, 2006). The straight lines are described by the equation DG z T ¼ DG z ES +DG b (1-n)+n DG s .…”

Section: Subsite Hydrophobicity and Subsite Role In Catalysis And Subsupporting

confidence: 53%

Subsite substrate specificity of midgut insect chymotrypsins

Sato¹,

Lopes²,

Juliano³

et al. 2008

Insect Biochemistry and Molecular Biology

View full text Add to dashboard Cite

Section: Subsite Hydrophobicity and Subsite Role In Catalysis And Subsupporting

confidence: 53%

Subsite substrate specificity of midgut insect chymotrypsins

Sato¹,

Lopes²,

Juliano³

et al. 2008

Insect Biochemistry and Molecular Biology

View full text Add to dashboard Cite

“…Similarly, serine (189), glycine (216) and glycine (226) form a deep hydrophobic pocket in chymotrypsins leading to a preference for phenylalanine at P1. In addition, adventitious contacts resulting from amino acids at sites other than the S1 pocket influence the kinetics of substrate binding and inhibition [26] -in fact, sub-sites of the trypsin catalytic triad that are known to influence substrate hydrolysis by selectively binding to the substrate or intermediate form(s) [27] can interact with up to position P 12 of the substrate [28]. In Fig.…”

Section: Molecular Diversity Versus Functional Diversitymentioning

confidence: 99%

Structural and functional diversities in lepidopteran serine proteases

Srinivasan

Giri

Gupta

2006

Cellular and Molecular Biology Letters

213

164

View full text Add to dashboard Cite

Primary protein-digestion in Lepidopteran larvae relies on serine proteases like trypsin and chymotrypsin. Efforts toward the classification and characterization of digestive proteases have unraveled a considerable diversity in the specificity and mechanistic classes of gut proteases. Though the evolutionary significance of mutations that lead to structural diversity in serine proteases has been well characterized, detailing the resultant functional diversity has continually posed a challenge to researchers. Functional diversity can be correlated to the adaptation of insects to various host-plants as well as to exposure of insects to naturally occurring antagonistic biomolecules such as plant-derived protease inhibitors (PIs) and lectins. Current research is focused on deciphering the changes in protease specificities and activities arising from altered amino acids at the active site, specificity-determining pockets and other regions, which influence activity. Some insight has been gained through in silico modeling and simulation experiments, aided by the limited availability of characterized proteases. We examine the structurally and functionally diverse Lepidopteran serine proteases, and assess their influence on larval digestive processes and on overall insect physiology.

show abstract

“…Although a lot of trypsin or trypsin-inhibitor complex structures were determined Craik, 1995, 1997;Song and Suh, 1998;Lin et al, 1993), there are no data using internally quenched substrates in defining the substrate specificity of trypsin nor in kinetically attempting to infer the role of trypsin subsites (other than S1) in catalysis, discounting a preliminary work (Marana et al, 2002). This results from difficulties in purifying large amounts of digestive insect trypsins and in the expression of active recombinant enzymes in heterologous systems or in insect cells (Volpicella et al, 2003).…”

Section: Introductionmentioning

confidence: 99%