Post Translational Modifications

Phosphorylation is a crucial mechanism in biological systems that regulates many cellular processes involved in growth, apoptosis, and signal transduction. It involves the transfer of a gamma-phosphate to specific amino acids such as serine, threonine, or tyrosine. For a significant number of proteins, phosphorylation is linked with protein activity and is essential to their functionality. Dysregulation of phosphorylation is implicated in a variety of diseases, including cancer, diabetes, and neurological disorders. Abnormal activation or inactivation of specific kinases or phosphatases can result in aberrant signaling pathways, leading to uncontrolled cell growth or impaired cellular function. Therefore, understanding the complex network of phosphorylation events in cells is crucial for developing targeted therapies to treat these diseases.

To aid detection of the phospho-proteome, RayBiotech offers phospho-specific antibody arrays in which up to 8,000 proteins can be screened simultaneously. Alternatively, targeted array panels and phosphorylation ELISAs are available to probe specific signaling pathways related to DNA damage, inflammation, tumorigenesis, and many other processes. Our repertoire of phosphorylation immunoassays features rapid, efficient protocols for high throughput data collection, empowering the researcher with precise, highly sensitive verification of pathway activation, detection of phosphorylation signatures, or enhancement of mass spectrophotometric protein analysis.

Phosphorylation is a highly reversible state, enabling rapid modulation of cellular activity. The addition and removal of phosphoryl groups to proteins is catalyzed by kinases and phosphatases, respectively.

Glycosylation is a fundamental process of the biosynthetic-secretory pathway of the ER and Golgi apparatus, involving the addition of sugar moieties to specific amino acids. This modification occurs in over half of all expressed proteins and can be categorized into groups based on the amino acid that links to the carbohydrate chain (N-, O-, C-). Each protein has the ability to be glycosylated at multiple sites, potentially with different linkages, enhancing the diversity of the proteome in a way that cannot be achieved by any other post-translational modification. Factors such as enzyme availability, amino acid sequence, and protein conformation all play a role in how glycosylation occurs. Abnormal glycosylation patterns can serve as markers for certain disease states, including cancer metastasis, diabetes mellitus, inflammatory bowel disease, systemic lupus erythematosus, and many other autoimmune conditions.

This diverse structure and complex composition also makes glycoproteins more difficult to analyze, and detection tools for glycobiology research are in limited supply. To address this challenge, RayBiotech has developed three different formats of glycobiology arrays utilizing microarray technology. The Glycan arrays, Glycome Arrays, and Lectin Arrays all utilize glass slide supports with fluorescent detection and serve as powerful tools for researchers to detect glycans and/or glycan-protein interactions.

RayBiotech has developed 3 different formats of glycobiology profiling arrays to help researchers detect glycans and/or glycan-protein interactions. All 3 formats feature glass slide supports with fluorescent detection.

Protein acetylation is a biochemical process whereby a lysine residue on a protein is modified through the addition of an acetyl group. This modification has significant implications for the structure and function of the protein. Initially identified on histones, acetylation increases the size of the side chain, attenuates the amino group's positive charge, and elevates the protein's hydrophobicity. The effects on DNA binding, enzymatic activity, protein-protein interactions, and protein degradation are far-reaching. Acetylation can stimulate gene expression by loosening the chromatin structure and rendering DNA more accessible to transcription factors and other regulatory proteins. Disrupted acetylation has been linked to various diseases, including cancer, neurodegenerative conditions, and metabolic disorders.

RayBio^® Human Protein Acetylation Antibody Arrays are designed for identifying the relative levels of acetylation of lysine in up to 8,000 different human proteins in cell lysate. Cell lysate is introduced into the wells of the antibody array glass slide. Then, a biotinylated anti-acetylated-lysine antibody is used to detect acetylated-lysine on target proteins. After incubation with a fluorescent dye-conjugated streptavidin, the slides are imaged using a laser scanner.

Protein acylation plays a significant role in cell signaling, development, and growth by covalently modifying proteins with lipids. This modification involves the addition of an acyl group, usually a fatty acid, to an amino acid residue. This changes the protein from hydrophilic to hydrophobic at one end, making it easier to interact with membranes. Protein acylation is a crucial aspect of many cellular processes relevant to physiology and diseases such as stability, localization, protein-protein interactions, and protein-DNA interactions. Furthermore, acylation plays a regulatory role in insulin secretion and insulin response pathways. Palmitoylation, the most extensively studied acyl modification, involves the addition of palmitate (a 16-carbon fatty acid) to a cysteine, and occasionally a threonine or serine residue. Unlike other acylation events, protein palmitoylation is reversible. The rapid and dynamic cycling between palmitoylation and de-palmitoylation plays an important role in membrane anchoring and trafficking between intracellular compartments.

RayBio^® Human Protein S-Acylation Antibody Arrays are designed for identifying the relative levels of S-acylation of cysteine in up to 8,000 different human proteins in various biological samples. The kits use a modified biotin-switch method to label the samples, wherein the biotin-labeled samples are added to antibody arrays, washed, and incubated with a fluorescent dye-conjugated streptavidin for imaging using a laser scanner. The arrays provide a quick and efficient way to monitor changes in protein S-acylation in experimental model systems.

Oxidative cell stress arises when the generation of reactive oxygen species (ROSs) and free radicals exceeds the cellular antioxidant defense system's capabilities. Among the key targets of oxidation, proteins take the spotlight due to their abundance and remarkable reactivity towards ROSs. Protein carbonylation occurs when ROSs react with specific amino acid side chains, primarily lysine, arginine, proline, and threonine residues. The presence of carbonylated proteins serves as valuable biomarkers for oxidative stress and has been linked to numerous diseases, including neurodegenerative disorders, cardiovascular diseases, diabetes, and aging-related conditions. Consequently, the detection and quantification of protein carbonylation plays a pivotal role in identifying oxidative stress biomarkers and devising strategies to mitigate their detrimental effects.

RayBio^® Human Protein Oxidation Antibody Arrays are designed to assess the relative levels of carbonylation in up to 8,000 different proteins in various biological samples. These innovative kits utilize a modified "biotin probes" method to enable sensitive and specific detection of carbonylated proteins. In this approach, carbonyl groups of proteins react with biotin-hydrazide to form unstable Schiff bases which are subsequently reduced to form stable hydrazine bonds. Following biotin-hydrazide labeling, samples are added to antibody arrays, washed, and incubated with a fluorescent dye-conjugated streptavidin for imaging using a laser scanner.

Tyrosine nitration involves the addition of a nitro group (-NO₂) to tyrosine residues in proteins, a modification mediated by reactive nitrogen species such as peroxynitrite (ONOO-), nitrogen dioxide (•NO₂), and nitronium ion (NO₂+). This process occurs under conditions of oxidative and nitrosative stress. While tyrosine is the primary target, other amino acids such as tryptophan, cysteine, and methionine can also undergo nitration due to their susceptibility to RNS. Other molecules susceptible to nitration include lipids, nucleic acids, and small molecules, broadening the impact of nitration in biological systems.

Lactylation is a post-translational modification in which a lactyl group, generated from cellular lactate, is covalently attached to lysine residues on proteins. Lactate, once thought of only as a metabolic waste product, is now recognized as a key signaling molecule. Cancer cells often convert glucose to lactate even in the presence of oxygen — a phenomenon known as the Warburg effect — underscoring lactate’s central role in cell metabolism. Through protein lactylation, this abundant metabolite directly modifies proteins and influences their function, linking energy metabolism to biological outcomes. Dysregulated lactylation has been associated with inflammation, immune evasion, fibrosis, and cancer progression, making it an important area of study for disease research.

Protein–Lys–NH₂ + HO–CH(CH₃)–COOH (Lactate) → Protein–Lys–NH–CO–CH(OH)–CH₃ (K-Lac)

RayBio^® Human Protein Lactylation Antibody Arrays provide a high-throughput approach to detect lysine lactylation across thousands of human proteins simultaneously. In this assay, cell lysates are incubated on antibody-coated glass slides, and captured proteins are probed with a biotinylated anti-lactyllysine antibody followed by fluorescent streptavidin for scanning. By enabling the detection of lactylation events in up to 8,000 proteins, these arrays offer researchers a convenient way to profile modification patterns and monitor pathway activation in diverse experimental systems.