The present invention relates to a method for modifying and purifying peptides comprising an immobilizing step, a modification step and a releasing step. In the immobilizing step, a crude linker-tagged peptide L-P is coupled to a solid support yielding an immobilized linker-tagged peptide S-L-P. Subsequently, the immobilized linker-tagged peptide S-L-P is modified with one or more organic molecules yielding an immobilized linker-tagged peptide S-L-mP. Finally, the modified peptide is released via a reduced intermediate RI. The linker molecule is a compound of formula 1, X—Tb—Va-U—Y—Z (1), which can be coupled to a purification resin via the moiety X and to a peptide via the moiety Y under the release of the leaving group Z. T is an optional spacer moiety and V is an optional electron withdrawing moiety. U is an aryl or 5- or 6-membered heteroaryl moiety bound to at least one electron withdrawing moiety V, W or E. The linker is stable under acidic conditions and releases the peptide upon addition of a reducing agent.

The present disclosure relates to nucleic acid-peptide-nucleic acid conjugate molecules and to methods for synthesizing nucleic acid-peptide-nucleic acid conjugate molecules. In some embodiments, a method for synthesizing a nucleic acid-peptide-nucleic acid conjugate molecule using proximity-enhanced synthesis includes covalently linking a peptide with a first nucleic acid strand via a first reaction, hybridizing the first nucleic acid strand with a second nucleic acid strand to bring the second nucleic acid strand in proximity to the peptide, and covalently linking the peptide with the second nucleic acid strand via a second reaction to provide the nucleic acid-peptide-nucleic acid conjugate molecule. In some embodiments, the peptide of the nucleic acid-peptide-nucleic acid conjugate molecule is a substrate for cleavage by an enzyme, such as matrix metalloproteinase-8 (MMP-8). Exemplary applications of the nucleic acid-peptide-nucleic acid conjugate molecule for drug delivery, molecular assembly of hybrid structures, and constraining the peptide to a biologically active conformation are also disclosed.

A method and a sensor for detecting L-arginine are provided. The method includes synthesizing ferrocene-functionalized hexadecapeptide dithiocyclopentane (FC-P16 Peptide), preparing a polypeptide composite membrane-modified electrode (FC-P16 Peptide/AuE), detecting L-Arg and other steps. The results show that the polypeptide composite membrane-modified electrode (FC-P16 Peptide/AuE) exhibits excellent electrochemical response properties to L-Arg. In 10 mmol/L phosphate-buffered saline (PBS, pH=7.4), the DPV response peak current of the polypeptide composite membrane-modified electrode has an excellent linear relationship with the L-Arg concentration of 1.0×10.sup.−13 mol/L to 1.0×10.sup.−7 mol/L, with a detection limit of 1.0×10.sup.−13 mol/L. With prominent reproducibility, repeatability and selectivity, the modified electrode has potential application in life science and nutritional health.

The present invention discloses a method for preparing a PEGylated biomolecule with controllable binding sites, comprising: (1) PEGylating a biomolecule; (2) binding a barrier to at least one binding site in the PEGylated biomolecule; (3) separating the PEGylated biomolecule not bound to the barrier; and (4) separating the barrier and the PEGylated biomolecule bound thereto. In another aspect, the present invention discloses a method for preparing a PEGylated IL-2 with controllable binding sites, comprising: (1) PEGylating to couple a PEG with IL-2; (2) binding the PEGylated IL-2 to an IL-2α receptor; (3) separating the PEGylated IL-2 not bound to the IL-2α receptor; and (4) separating the IL-2α receptor and the PEGylated IL-2 bound thereto. By regulating the binding sites of IL-2, only 1 or 2 PEGs are added during PEGylation.

Described herein are methods of syntheses and therapeutic uses of covalently modified peptides and/or proteins. The covalently modified peptides and/or proteins allow for improved pharmaceutical properties of peptide and protein-based therapeutics.

The disclosure is directed to compounds and methods for preparing purified macrocyclic peptide using “catch-release” methods. These methods comprise reacting a free amino group of a resin-bound linear peptide with an azide- or alkyne-functionalized cap to form a resin-bound capped linear peptide having an azide- or alkyne-functionalized cap; cleaving the capped linear peptide from the resin to form a free capped linear peptide having an azide- or alkyne-functionalized cap; reacting the free capped linear peptide having an azide-functionalized cap with an alkyne-functionalized catch resin, or reacting the free capped linear peptide having an akynyl-functionalized cap with an azide functionalized catch resin, to form a catch-resin bound capped linear peptide; reacting the catch-resin bound capped linear peptide under conditions sufficient to effect macrocyclization of the linear peptide and release of the macrocyclic peptide from the catch resin.

Provided herein are thiosuccinyl-crosslinked hemoglobin analogs useful as blood replacement agents, pharmaceutical compositions comprising the same and the methods of use and preparation thereof.

The present disclosure relates generally to methods of preparing glycoconjugates containing a saccharide conjugated to a carrier protein by use of stable nitroxyl radical related agent/oxidant as an oxidizing agent, to immunogenic compositions comprising such glycoconjugates, and to methods for the use of such glycoconjugates and immunogenic compositions.

The invention provides a new oligopeptide linker intermediate and a preparation method thereof. The preparation method of the oligopeptide intermediate is easily carried out under mild reaction conditions, and since almost no side reactions occur in the reaction, the method produces a high-purity product with fewer impurities and easy to be purified, achieving unexpected technical effects.

The present invention relates to peptide modifier compounds of Formula (1), or a salt thereof, wherein: a is an integer from 1 to 10, more preferably from 1 to 3; b is an integer from 0 to 7; Z is a terminal group and Y is a bivalent group. Further aspects of the invention relate to intermediates in the preparation of compounds of Formula (1), and the use of compounds of Formula 1 in the synthesis of peptide derivatives. ##STR00001##