Methods that stabilize allosteric cell attachment proteins in either an active or inactive conformation enable toggling a protein between conformational states by restricting the repacking of side chains that occurs during the conformational transition. This restriction traps the protein in the desired high affinity or low affinity state. An allosteric cell attachment protein stabilized in an active (high-affinity) or inactive (low-affinity) conformation is stabilized by the substitution of a hydrophobic amino acid residue with a charged amino acid, in some embodiments, the attachment protein is bacterial. In some embodiments, the attachment protein is viral, in some embodiments, the protein is a bacterial adhesin.

The invention described herein includes a novel platform for the development of novel shapeshifting drug-like compounds that overcome physical mass limitations as they possess the ability to interconvert internally and spontaneously, i.e., shapeshift, between multiple chemical structures with varying pharmacophore properties. In one preferred embodiment, the invention include systems, methods, and compositions for the synthesis of novel bullvalene amino acid (Bvas) compounds that may further be incorporated into Shape Shifting Cyclic Peptides (SSCP) with varying pharmacophore properties and their use as novel therapeutic compounds.

Some embodiments of the invention involve methods for introduction of various functional groups onto polypeptides, peptides and proteins by alkylation of thioether (a.k.a. sulfide) groups by ring opening reactions, creating new compositions of matter that may be useful for medical therapeutic or diagnostic applications. The thioether groups may either be present in the polypeptides, or may be added to polypeptides by chemical modification, such as by alkylation of thiol (sulfhydryl) groups.

The present invention is broadly concerned with new in vitro glycosylation methods that provide rational approaches for producing glycosylated proteins, and the use of glycosylated proteins. In more detail, the present invention comprises methods of glycosylating a starting protein having an amino sidechain with a nucleophilic moiety, comprising the step of reacting the protein with a carbohydrate having an oxazoline moiety on the reducing end thereof, to covalently bond the amino sidechain of the starting protein with the oxazoline moiety, wherein the glycosylated protein substantially retains the structure and function of the starting protein. Target proteins include oxidase, oxidoreductase and dehydrogenase enzymes. The glycosylated proteins advantageously have molecular weights of at least about 7500 Daltons. In a further embodiment, the present invention concerns the use of glycosylated proteins, fabricated by the methods disclosed herein, in the assembly of amperometric biosensors.

Presented is a method to incorporate 2-thiohistidine (2-thioHis) into a peptide. Also provided are peptides incorporating 2-thioHis, compositions, and methods of using the peptides incorporating 2-thioHis. The methods may be methods for scavenging metals and/or radicals or reducing oxidative stress. 2-thioHis has the following structure:

##STR00001##

The invention features compositions and methods for site-specific modification of proteins by incorporation of an aldehyde tag. Enzymatic modification at a sulfatase motif of the aldehyde tag through action of a formylglycine generating enzyme (FGE) generates a formylglycine (FGly) residue. The aldehyde moiety of FGly residue can be exploited as a chemical handle for site-specific attachment of a moiety of interest to a polypeptide.

The present invention provides a process for the production of compound (III) or a deprotected product thereof: comprising reacting compound (II) with chloroacetic acid, in the presence of a reducing agent; wherein PG is a protecting group and R is OH in a suitably protected form or (A). The invention further provides intermediate compounds formed in the process of the invention, and processes for the production of intermediate compounds. ##STR00001##

The present invention provides a process for the production of compound (III) or a deprotected product thereof: comprising reacting compound (II) with chloroacetic acid, in the presence of a reducing agent; wherein PG is a protecting group and R is OH in a suitably protected form or (A). The invention further provides intermediate compounds formed in the process of the invention, and processes for the production of intermediate compounds. ##STR00001##

Novel synthesized amino acids of glutamine and lysine that are directly PEGylated with small, monodisperse PEGs, and a novel process for creating novel amino acid monomers using PEGylation. These amino acids are readily incorporated into peptides for a range of different applications.

Methodology was developed for transformation of methionine residues into homocysteine derivatives. Methionine residues can undergo alkylation reactions at low pH to yield sulfonium ions, which can then be selectively demethylated to give alkyl homocysteine residues. This process tolerates many functional groups.