The α-Chymotrypsin-Catalyzed Hydrolysis of a Series of Analogs of Acetylglycine Methyl Ester<sup>*</sup>

Wolf, John P.; Niemann, Carl

doi:10.1021/bi00903a017

Cited by 30 publications

(9 citation statements)

References 14 publications

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“…Steric effects arising from the structure of the substrate molecule have been encountered earlier Roger l. peterson, konrad w. hubele, and carl niemann Biochemistry (Almond et al, 1962;Wolf and Niemann, 1963b; Waite and Niemann, 1962; Jones and Niemann, 1962;Abrash, 1961). They have arisen from replacement of the -hydrogen atom by a bulkier group or by ßbranching of the side chain of both aliphatic and aromatic a-N-acylated--amino acid derivatives.…”

Section: Discussionmentioning

confidence: 85%

“…However, it should be noted that the observations of Seligman and Wolf (1951) led these investigators to characterize --phthaloyl-DL-phenylalanine ß-naphthol ester as a substrate of moderate reactivity. Kuk-Meri and Lichtenstein (1957) reported that --methyl-D-and L-phenylalanine ethyl ester were not hydrolyzed by -chymotrypsin and Wolf and Niemann (1963b) noted that, in contrast to acetylglycine methyl ester, acetyl-N-methylglycine methyl ester was incapable of functioning as a substrate of this enzyme. However, interpretation of the latter observation in terms of abolition of hydrogen bonding involving the -amido hydrogen atom lost much of its force when it was found that the kinetic constants for the -chymotrypsin-catalyzed hydrolysis of acetylglycine methyl ester and of methyl levulinate were essentially indistinguishable (Wolf and Niemann, 1963b).…”

Section: Discussionmentioning

confidence: 99%

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The α-Chymotrypsin-catalyzed Hydrolysis of α-N and O-Alkyl Derivatives of α-N-Acetyl-L-tyrosine Methyl Ester^*

Peterson¹,

Hubele²,

Niemann³

1963

Biochemistry

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An investigation of the kinetics of the -chymotrypsin-catalyzed hydrolysis of --acetyl--jV-methyl-L-tyrosine methyl ester and of --acetyl-O-methyl, -ethyl, and -isopropyl-Ltyrosine methyl ester, in aqueous solutions at 25.0°, pH 7.90, and 0.10 m in sodium chloride, has shown that the lesser reactivity of these substrates, relative to -lV-acetyl-L-tyrosine methyl ester, is not due to an inability of the modified molecules to combine with the active site of the enzyme. The diminished reactivity arises from a less favorable orientation of the modified molecules when present at the active site. «-.ZV-Acylated aromatic -amino acid esters are among the more reactive substrates of a-chymotrypsin and are frequently employed in studies on the mechanism of action of this enzyme. However, there are many features of the structural specificity of a-chymo-

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Section: Discussionmentioning

confidence: 85%

Section: Discussionmentioning

confidence: 99%

The α-Chymotrypsin-catalyzed Hydrolysis of α-N and O-Alkyl Derivatives of α-N-Acetyl-L-tyrosine Methyl Ester^*

Peterson¹,

Hubele²,

Niemann³

1963

Biochemistry

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“…In the absence of more quantitative information we can assert that the relative reactivities of the L-antipodes of the following a-IV-acetyl methyl esters are in the order, phenylalanine > > alanine > valine > > 3.3dimethylphenylalanine (Jones andNiemann, 1962, 1963; Wolf and Niemann, 1963). Replacement of a 3-hydrogen atom of the alanine derivative by a phenyl group causes a substantial increase in reactivity.…”

Section: Discussionmentioning

confidence: 99%

Steric Hindrance in α-Chymotrypsin-catalyzed Reactions^*

Abrash¹,

Niemann²

1963

Biochemistry

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“…Azocoll was a gift from Dr I. Mandl. Ac-Gly-OEt was synthesized according to the procedure of Wolf and Niemann [8].…”

Section: Substratesmentioning

confidence: 99%

Allosteric Activation of the Hydrolysis of Specific Substrates by Chymotrypsin

et al. 1976

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A variety of azobenzene compounds having bis-quaternary nitrogens have been shown to accelerate the hydrolyis by chymotrypsin of certain specific substrates by an allosteric mechanism. One of the most potent, 2,2'-bis[a-(benzyldimethylammonium)methyl]azobenzene dibromide (2,2'-Q-Bzl) accelerated the hydrolysis of glutaryl-L-phenylalanine p-nitroanilide 40-fold at saturating concentration. Acceleration was by increasing k,,, without altering K,. The hydrolysis of acetyl-Ltyrosine p-nitroanilide and acetyl-L-tyrosine anilide was also accelerated by Q-Bzl (25-fold and 1.8-fold respectively) while the hydrolysis of hemoglobin, azocoll and a number of esters was not affected. The inactivation of chymotrypsin by diphenylcarbamyl chloride and diphenylcarbamyl fluoride was accelerated by 2,2'-Q-Bzl. Reactivation in the presence of NH20H was also accelerated, but in the absence of added nucleophile (ie. of NH20H) no increase in rate was detectable. An allosteric effector was covalently attached to chymotrypsinogen A by reaction with 2,2'-bis[or-(o-bromomethylbenzyldimethylammonium)methyl]azobenezene dibromide. The product, when converted to active enzyme, was about 4 times more active than chymotrypsin as a result of an increase in k,,, of hydrolysis; K , was unaffected. The mechanism of the allosteric acceleration process is not known but, because for all of the substrates affected acylation of the enzyme is rate-limiting, it is tentatively suggested that the effectors facilitate proton transfer to the leaving group by an inductive effect on the 'charge relay system'. Spectral studies indicate that the allosteric site is a portion of the enzyme with a polarity near that of water, possibly on the outside surface of the enzyme molecule. In a preliminary communication [l] we reported acceleration of the chymotryptic hydrolysis of certainAbbreviations. Glt-Phe-Nan, glutaryl-L-phenylalanine p-nitroanilide ; Ac-Tyr-Nan, a-N-acetyl-DL-tyrosine p-nitroanilide; Z-Tyr-NHOH, carbobenzoxy-L-tyrosine hydroxamide; Ac-Tyr-An,, a-N-acetyl-L-tyrosine anilide ; Q-Me, bis[a-(trimethy1ammonium)methyllazobenzene dibromide; Q-Bzl, bis[a-(benzyldimethylammonium)methyl]azobenzene dibromide; Q-Nbzl, bis[a-(p-nitrobenzyldimethylammonium)methyl]azobenzene dibromide; Q-BrMeBzl, 2,2' -bis[a-(0 -bromomethylbenzyldimethylammonium)methyl]azobenzene dibromide; K-Bzl, 2,2'-[a-(benzy1dimethylammonium)-methyl]diketobenzene dibromide; Ac-Tyr-OEt, a-N-acetyl-L-tyrosine ethyl ester; Ac-Gly-OEt, a-A'-acetyl-glycine ethyl ester; Bz-GlyOEt, a-N-benzoyl-glycine ethyl ester; PhZNCF and Ph,NCchymotrypsin, diphenylcarbamyl chloride, fluoride and chymotrypsin, respectively; Ac-ONp, p-nitrophenylacetate ; Bz-Arg-Nan, a-Nbenzoyl-DL-arginine p-nitroanilide.Enzyme. a-Chymotrypsin or chymotrypsinogen A (EC 3.4.21.1).specific substrates by a number of compounds having the general structure :QMe: R=CH3 cis and rrans isomers Q-BrMeBzl: R=CH2Acceleration of substrate hydrolysis (for example, Glt-Phe-Nan) occurred as a result of the binding of the activator molecule to a site...

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The α-Chymotrypsin-Catalyzed Hydrolysis of a Series of Analogs of Acetylglycine Methyl Ester^*

Cited by 30 publications

References 14 publications

The α-Chymotrypsin-catalyzed Hydrolysis of α-N and O-Alkyl Derivatives of α-N-Acetyl-L-tyrosine Methyl Ester^*

The α-Chymotrypsin-catalyzed Hydrolysis of α-N and O-Alkyl Derivatives of α-N-Acetyl-L-tyrosine Methyl Ester^*

Steric Hindrance in α-Chymotrypsin-catalyzed Reactions^*

Allosteric Activation of the Hydrolysis of Specific Substrates by Chymotrypsin

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The α-Chymotrypsin-Catalyzed Hydrolysis of a Series of Analogs of Acetylglycine Methyl Ester*

Cited by 30 publications

References 14 publications

The α-Chymotrypsin-catalyzed Hydrolysis of α-N and O-Alkyl Derivatives of α-N-Acetyl-L-tyrosine Methyl Ester*

The α-Chymotrypsin-catalyzed Hydrolysis of α-N and O-Alkyl Derivatives of α-N-Acetyl-L-tyrosine Methyl Ester*

Steric Hindrance in α-Chymotrypsin-catalyzed Reactions*

Allosteric Activation of the Hydrolysis of Specific Substrates by Chymotrypsin

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Product

Resources

About

The α-Chymotrypsin-Catalyzed Hydrolysis of a Series of Analogs of Acetylglycine Methyl Ester^*

The α-Chymotrypsin-catalyzed Hydrolysis of α-N and O-Alkyl Derivatives of α-N-Acetyl-L-tyrosine Methyl Ester^*

The α-Chymotrypsin-catalyzed Hydrolysis of α-N and O-Alkyl Derivatives of α-N-Acetyl-L-tyrosine Methyl Ester^*

Steric Hindrance in α-Chymotrypsin-catalyzed Reactions^*