摘要:
The present invention concerns a beverage containing proteins and/or peptides and is characterized in that it contains Cereal-LT and/or homologues as herein defined and/or a modified Cereal-LTP fraction obtainable from the Cereal-LTP and/or homologues by heating, boiling and/or mashing the Cereal-LTP and/or homologues in water at a pH between 3 and 7. The invention also concerns a method for preparing it and a use of a foam-forming additive.
摘要:
An auxiliary substance such as a label, support, or bioactive agent is attached to a protein at a site that is remote from the active site of the protein by the use of exopeptidase and a nucleophile which is an amino acid, amino acid derivative, amine or alcohol. In one embodiment, the nucleophile is attached to the carboxy terminus of a protein by catalysis with exopeptidase to form an adduct and then the adduct or its combination with a linker arm is bound to the auxiliary substance. In another embodiment, the auxiliary substance or its combination with a linker arm is bound to the nucleophile to form an intermediate substance which is then coupled by catalysis with exopeptidase to the carboxy terminus of a protein.
摘要:
The invention provides customized proteases (i.e., mutant enzymes), methods of making customized proteases, as well as methods of using customized proteases. The customized proteases of the invention are derived from the known proteases. Altered transacylation reactions include the capability to perform transacylation reactions not substantially catalyzed by the known protease or the capability to perform transacylation reactions with improved yields, or both. The methods of the invention provide for customized proteases through site specific or random mutagenesis of the active site amino acids of the known proteases. The invention also provides for methods of using the customized proteases to prepare a preselected transacylation products. The preselected transacylation products produced can be modified by substitution at the N- or C-terminal with nucleophiles such as L-amino acids, D-amino acids, amino acid amides, and radioactive amino acids.
摘要:
A method for transamidating a peptide substrate having a P.sub.1 amino acid residue with a positively charged side chain. According to the invention, carboxypeptidase Y is modified to substitute at least one amino acid having a negatively charged side chain in an S.sub.1 subsite. Additionally, the modified carboxypeptidase Y can include substituted amino acid residues in an S.sub.1 ', S.sub.2 and/or S.sub.3 subsite to accommodate a specific peptide substrate.
摘要:
A process for preparing C-terminally amidated peptides, Peptide-NH.sub.2, is presented. In a first step, a substrate component is reacted with a nucleophile component in the presence of trypsin or a carboxypeptidase using as nucleophile a compound NH.sub.2 -R to form a first reaction product Peptide-NH-R. In a second step, the first reaction product is non-enzymatically chemically cleaved to form the C-terminally amidated product, Peptide-NH.sub.2. The substrate component is selected from a) peptide derivatives Peptide-X-Y, where X is an amino acid or peptide residue and Y is OH, OMe or C-terminal modification and c) C-terminally esterified peptides, Peptide-OR', where R' is alkyl, aryl, heteroaryl, or aralkyl. The nucleophile component is selected from ##STR1## wherein A-F and A'-E' are carbon atoms or up to two hetero atoms, Y is H, alkyl, aryl, aralkyl, oxo or carboxy, X.sup.1 -X.sup.5 are H or various substituents. The cleavage may be induced by photolysis, solvolysis, reduction, rearrangement elimination, or oxidation. The process may be adapted to enzymatic synthesis and lends itself to C-terminal amidation of many types of peptides.
摘要:
Novel chemically modified detergent enzymes are provided, wherein one or more methionines have been mutated into cysteines, said cysteines subsequently being chemically modified in order to confer the enzyme improved stability towards oxidative agents. A novel process for stabilizing detergent enzymes against oxidation is also provided. Furthermore, there are provided detergent compositions comprising these novel oxidation stable detergent enzymes.
摘要:
The B-30 amino acid in insulins is replaced enzymatically byreacting as substrate component the selected insulin Ins-X, wherein X represents the B-30 amino acidwith an amine component selected from the group consisting of(a) amino acids of the formulaH--B--OHwherein B is an amino acid residue,(b) optionally N-substituted amino acid amides of the formulaH--B--NR.sup.1 R.sup.2wherein B is an amino acid residue and R.sup.1 and R.sup.2 are independently selected from the group consisting of hydrogen, amino, hydroxy, alkyl, cycloalkyl, aryl, heteroaryl and aralkyl or R.sup.1 and R.sup.2 together with the nitrogen atom form a heterocyclic group which may contain a further hetero atom, and(c) amino acid esters of the formulaH--B--OR.sup.3, H--B--SR.sup.3 or H--B--SeR.sup.3wherein B is am amino acid residue and R.sup.3 represents alkyl, cycloalkyl, aryl, heteroaryl or aralkylin the presence of an L-specific serine or thiol carboxypeptidase enzyme, preferably carboxypeptidase-Y, in an aqueous solution or dispersion having a pH from about 7 to 10.5, thereby to form an insulin derivativeIns--B--OH, Ins--B--NR.sup.1 R.sup.2, Ins--B--B--NR.sup.1 R.sup.2,Ins--B--OR.sup.3, Ins--B--SR.sup.3 or Ins--B--SeR.sup.3and subsequently cleaving a group --NR.sup.1 R.sup.2, --B--NR.sup.1 R.sup.2, --OR.sup.3, --SR.sup.3 or SeR.sup.3, if desired, preferably by using a carboxypeptidase enzyme. The cleaving may also be performed on derivatives obtained by other methods.By using porcine insulin as substrate component and threonine as the amino acid forming part of the amine component human insulin is obtained.
摘要:
An insulin such as porcine insulin is reacted enzymatically with an L-amino acid, amide, or ester in the presence of L-specific serine carboxypeptidase modified by reaction with divalent metal ions in aqueous solution or dispersion containing F.sup.-, Cl.sup.-, Br.sup.-, I.sup.-, CN.sup.-, or SCN.sup.-.