Binding of competitive inhibitors to δ-chymotrypsin in the alkaline pH region. Competitive inhibition kinetics and proton-uptake measurements

Valenzuela, Pablo; Bender, Myron L.

doi:10.1021/bi00814a008

Cited by 31 publications

(2 citation statements)

References 22 publications

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“…at least in part, to the ability of the latter two to interact with cyanuric acid at some specific center, which is not present in the enzyme. This difference in binding of cyanuric acid may be related to the known difference in binding of competitive inhibitors by the a and enzymes (Valenzuela and Bender, 1970). The interaction with cyanuric acid seems to be strongest in the y enzyme and to increase in it with increasing temperature and pH.…”

Section: Discussionmentioning

confidence: 96%

Tyrosine environment differences in the chymotrypsins

Gorbunoff¹,

Ettinger²

1971

Biochemistry

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Section: Discussionmentioning

confidence: 96%

Tyrosine environment differences in the chymotrypsins

Gorbunoff¹,

Ettinger²

1971

Biochemistry

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“…We were unable to find a procedure for isolating benzobenzvalene free of naphthalene although repeated crystallization of naphthalene from the mixture dissolved in isopentane or methanol gave a small sample containing only 9% naphthalene. Naphthvalene showed the following characteristics: colorless liquid; nmr (CC14) 3.18 (symmetrical multiple!, 4.05 ), 6.17 (1.5-Hz triplet, 1.98 ), 7.60 (1.5-Hz triplet, 1.97 H); uv (in cyclohexane, after subtracting that of naphthalene impurity) Xmax (e) 278 (494), 271 (465), 264 (375), 235 nm (975); stable at room temperature; heated in CCL (175°, 10 min) it gives benzofulvene (36% yield)11 and polymer, but not naphthalene;12 U/" (CCL,, 75°) ~1.3 days.…”

mentioning

confidence: 98%

Benzvalene synthesis

Katz¹,

Wang²,

Acton³

1971

J. Am. Chem. Soc.

154

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Among interesting chemical structures, that of the valence isomer of benzene, benzvalene (I), is one of the most fundamental and one of the rarest. Benzvalene has been synthesized by photolyzing benzene,1,2 but because its photochemical decomposition is benzene sensitized,lb the steady-state concentrations do not exceed 0.05 %,la and although the conversion can be increased to 1 % by dilution with hexadecane,13 the yield is still small and the product diluted by solvent. We are reporting a simple procedure for synthesizing the benzvalene ring system that makes this rare hydrocarbon abundant. IIThe procedure is indicated in reaction 1. Reasons for expecting its efficacy have been enumerated pre-++ CHA + CH3Li + (^) (1) viously,3 but the best reason is that the analogous reaction works, using the cyclononatetraenyl anion,3•4 and gives as the major product isobullvalene (II), the corresponding valence tautomer of cyclodecapentaene.An important consideration in effecting the reaction is the choice of solvent, as carbonoid reactions of lithium halomethides occur best in those that solvate lithium cations poorly.3 However, the commonly used solvent, diethyl ether,3,3af' does not dissolve lithium cyclopentadienide. By contrast, dimethyl ether does, and if reaction 1 could be effected using it, the isolation of large quantities of benzvalene would be easy because distillation should separate it from the much lower boiling solvent. In fact, reaction 1 can be effected in dimethyl ether and gives a 24% yield of benzvalene,7 samples of which were isolated pure and identified by proton nmr spectroscopy. However, we were discouraged from investigating its large-scale isolation pure when the resonance energy of benzene and the strain energy of small-ring compounds were called to our attention by the benzvalene exploding.8•9(1) (a

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Stability and activity modulation of chymotrypsins in AOT reversed micelles by protein–interface interaction: Interaction of α-chymotrypsin with a negative interface leads to a cooperative breakage of a salt bridge that keeps the catalytic active conformation (Ile16–Asp194)

Almeida

Valente

Chaimovich

1998

Biotechnol. Bioeng.

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The stability of α‐chymotrypsin and δ‐chymotrypsin was studied in reversed micelles of sodium bis(2‐ethylhexyl)sulfosuccinate (AOT) in isooctane. α‐Chymotrypsin is inactivated at the interface and at the water pool, while δ‐chymotrypsin is inactivated only at the water pool. The mechanism of inactivation at the interface is related to the interaction of N‐terminal group alanine 149 (absent in δ‐chymotrypsin) with the negative interface. The dependence of enzyme activity on water content of these two enzymes in reversed micelles of AOT is also related with the interface interaction, since δ‐chymotrypsin does not have a bell‐shaped curve as observed for α‐chymotrypsin. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 59:360–363, 1998.

show abstract

Binding of competitive inhibitors to δ-chymotrypsin in the alkaline pH region. Competitive inhibition kinetics and proton-uptake measurements

Cited by 31 publications

References 22 publications

Tyrosine environment differences in the chymotrypsins

Tyrosine environment differences in the chymotrypsins

Benzvalene synthesis

Stability and activity modulation of chymotrypsins in AOT reversed micelles by protein–interface interaction: Interaction of α-chymotrypsin with a negative interface leads to a cooperative breakage of a salt bridge that keeps the catalytic active conformation (Ile16–Asp194)

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