Boc-Pro-PAM resin - extent of labeling: ~0.7mmol/g loading

Cat. No.: B476082

GRADE & PURITY extent of labeling: ~0.7mmol/g loading

Synonyms

Boc-L-proline bound to PAM resin

Storage

Store at 2-8°C

Shipped In

Wet ice

Specifications

동의어

Boc-L-proline bound to PAM resin

사양 및 순도

extent of labeling: ~0.7mmol/g loading

보관 조건

Store at 2-8°C

배송

Wet ice

이 제품은 콜드 체인 배송이 필요합니다.지상 및 기타 경제 서비스는 사용할 수 없습니다.

Application Protocols

• No vendor-validated protocols are provided for this specific SKU. The following are general/literature procedures for Boc SPPS on PAM resins; adjust to your equipment and consult the CoA for resin-specific parameters.

• Representative startup procedure (general)

  1. Swell 0.25–1.0 g resin in DCM (10 mL/g) for 30 min; exchange to DMF (3–5×).
  2. Boc deprotection: Treat with 50% TFA/DCM, 2×5–10 min; wash thoroughly; neutralize with 10–20% DIEA in DMF, 2×5 min.
  3. Coupling cycle: Pre-activate Boc-AA (3–5 eq) with DIC (3–5 eq) + Oxyma (3–5 eq) in DMF 5–10 min; add to resin and agitate 45–60 min. Repeat or extend as needed.
  4. Wash and cap unreacted amines (Ac2O/DIEA, 5–10 min). Iterate cycles.
  5. After chain assembly, dry resin thoroughly before cleavage.
  6. Cleavage: HF at 0 °C for 30–60 min with appropriate scavengers; quench and work up under established HF procedures.

• Monitoring and analytics

  • Use chloranil test when coupling to proline; resume Kaiser test after installing a primary amine residue.
  • Analyze crude by LC–MS/RP-HPLC; adjust coupling/deprotection times based on crude profiles.

• Notes

  • Parameters such as resin loading, bead size, and crosslinking are item-specific and are Not specified for this item; refer to CoA/Spec Sheet.

Biological Roles

• Scope: Information below concerns L-proline and peptide context in general; it does not describe any biological activity of the resin itself.

• Proline in proteins/peptides (general/literature)

  • Structural role: Proline’s pyrrolidine ring constrains backbone φ/ψ angles, often inducing turns and kinks; it disrupts α-helices and can stabilize polyproline helices (PPI, PPII).
  • Conformational effects: Proline cis/trans isomerization at X–Pro peptide bonds modulates folding kinetics and biological recognition; prolyl isomerases (e.g., Pin1) regulate this in cells.
  • Recognition motifs: Proline-rich sequences (PXXP) are recognized by SH3/WW domains in signaling proteins.
  • C-terminal amide: Many bioactive peptides are amidated at the C-terminus to modulate stability and receptor interactions; PAM resin provides this amide functionality after cleavage (general note).

• Implication for SPPS

  • When designing bioactive peptides, the presence of C-terminal –CONH2 (delivered by PAM) and strategic placement of Pro can be crucial for mimicking native conformations. The resin enables access to such constructs for biochemical research.

• Compliance

  • No medical or clinical claims are made here. Product is for research use only (Product Data).

Buffer Applications

• Not typically applicable. This product is a solid-phase synthesis resin, not a buffering agent. It does not function as a pH buffer or as a component of electrophoresis/cell culture buffers.
• For practical lab handling, standard organic solvents (e.g., DMF, DCM) are used for swelling, deprotection, and coupling rather than aqueous buffers. See the Solvent Selection, Reaction & Applications, and Reaction Conditions sections for relevant details.

Green Alternatives

• Considerations (general/literature)

  • PAM/Boc routes typically require HF cleavage and often use chlorinated solvents (DCM) and DMF. Greener strategies aim to avoid HF and reduce hazardous solvents while maintaining peptide quality.

• Alternative linkers/strategies

  • Fmoc-Rink amide resin: Delivers C-terminal amide without HF; cleavage in TFA with scavengers. Replaces Boc/TFA cycles with Fmoc/piperidine (or piperazine). Widely considered safer and greener than HF-based protocols.
  • Greener deprotections: 20% piperidine can be replaced by 0.5 M DBU/piperazine or newer secondary amines to reduce toxicity (literature) when using Fmoc chemistry.

• Solvent substitutions

  • DMF replacements: N-Butylpyrrolidone (NBP), NEP, or PolarClean® blends have shown comparable performance in SPPS with reduced hazard profiles.
  • DCM replacements: 2-MeTHF, CPME, EtOAc, or toluene can be used where swelling and reactivity are acceptable; validate per sequence.

• Comparison (general summary)

  • Boc-Pro-PAM (this item): Highest fidelity with classical Boc protocols; requires HF for global deprotection/cleavage; excellent for certain legacy processes.
  • Fmoc-Rink amide: No HF, broad adoption, easier waste handling; may require different optimization for difficult sequences.

• Trade-offs

  • Avoiding HF improves safety and environmental profile but may necessitate redevelopment of conditions and may affect certain side-chain protection strategies. Always perform pilot trials when changing platforms.

Pharmaceutical Uses

• Scope: Information below refers to manufacturing/formulation context, not therapeutic claims. Product is for research use only (Product Data).

• Role in development and manufacturing (general/literature)

  • Preloaded Boc-Pro-PAM resin is a process material/support used to assemble peptide candidates that require a C-terminal amide and a C-terminal L-proline residue (prolinamide). It is not an excipient and is not present in the final drug product.
  • Relevance: Useful for route scouting when legacy Boc/HF platforms are under consideration, or when reproducing historical syntheses. However, many GMP environments prefer HF-free routes (e.g., Fmoc-Rink amide) for safety and regulatory simplicity.

• Documentation considerations

  • For translational work, comprehensive vendor CoA, resin loading certification, extractables/leachables risk assessment, and traceability of raw materials are typically required. Since item-specific grade data are not provided here, consult CoA/Spec Sheet for suitability assessments.

• Process implications

  • PAM cleavage produces the desired C-terminal –CONH2 without additional amidation steps, simplifying downstream purification for amide-terminated peptides (general note).

Physical Properties

• Item-specific values (from Product Data)

  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.
  • Resin loading (mmol/g), bead size, crosslinking, and swelling: Not specified for this item; refer to CoA/Spec Sheet.

• General/literature characteristics of PAM/PS Boc-preloaded resins

  • Physical state: Free-flowing polymer beads (typically 75–150 µm for manual SPPS; wider ranges exist).
  • Density (apparent): Typically ~0.3–0.6 g/mL as packed wet resin; true polymer density near ~1.05 g/mL (literature, varies by crosslinking/solvent).
  • Solvent compatibility: Swell well in DCM, DCE, DMF, NMP, THF, toluene; limited swelling in MeOH/EtOH; essentially insoluble in water (literature).
  • Typical loading range: ~0.3–1.0 mmol/g depending on manufacturer/spec (literature). Use actual CoA for stoichiometry.
  • Thermal/chemical stability: Stable to standard Boc SPPS conditions (TFA for Boc removal; base washes; coupling reagents) and cleaved by anhydrous HF with scavengers (literature).

• Practical notes (general)

  • Swelling is solvent- and crosslinking-dependent; equilibrate beads in the working solvent (e.g., DMF, DCM) before use to ensure efficient diffusion and coupling.
  • Accurately determine effective loading (if unspecified) by independent assay (e.g., quantitative Boc determination or post-coupling color tests); do not rely on literature averages for stoichiometry.

Quality and Grades

• Item-specific status (from Product Data)

  • Grade/Purity: Not specified for this item; refer to CoA/Spec Sheet.
  • Research Use: For research use only (Product Data). Not for human or animal therapeutic use.

• What “preloaded Boc-Pro-PAM resin” denotes (general/literature)

  • Preloaded: The first residue (L-Proline) is already attached to the PAM linker; the N-terminus is protected with Boc and ready for Boc SPPS cycles.
  • PAM linker: Engineered to deliver a C-terminal amide upon HF cleavage. Particularly useful when a –CONH2 C-terminus is desired.
  • Typical quality controls: Manufacturers often report loading (mmol/g), bead size, crosslinking percentage, residual monomers/metals, and identity tests. Since item-specific values are not provided here, consult the CoA for exact parameters.

• Practical QA considerations for users (general)

  • Verification of loading: Because proline is a secondary amine, traditional Kaiser (ninhydrin) tests are not suitable for detecting unreacted Pro N-termini. Use the chloranil test for secondary amines to monitor coupling to Pro or rely on quantitative Boc deprotection and subsequent color tests after installing a primary amine residue.
  • Low-substitution vs high-substitution resins: Lower loadings (~0.3–0.5 mmol/g) can improve synthesis of long or aggregation-prone sequences by reducing on-resin crowding; higher loadings increase throughput for short peptides.
  • UV cutoffs, trace metals, and stabilizers are not typically specified for polymeric resins; follow the CoA/SDS for any additional specifications.

Reaction and Applications

• Intended use (general/literature)

  • Solid-phase peptide synthesis under Boc chemistry, starting from an on-resin L-proline residue and targeting C-terminal amide peptides after HF cleavage.

• Workflow outline

  1. Swell resin (DCM, then DMF).
  2. Remove Boc with TFA (commonly 50% TFA/DCM, 2×5–10 min), wash, and neutralize (DIEA).
  3. Couple next Nα-protected (Boc) amino acid using DIC/HOBt or DIC/Oxyma (or uronium reagents) with base.
  4. Wash, monitor coupling (chloranil test useful with secondary amines), and iterate cycles.
  5. Side-chain protection per Boc strategy; final HF cleavage with scavengers affords the fully deprotected peptide bearing a C-terminal prolinamide.

• Notes specific to proline (literature)

  • Proline’s secondary amine can slow acylation; ensure full activation (e.g., pre-activation with DIC/Oxyma) and consider double coupling.
  • Racemization is generally low for Pro, but maintain low basicity during activation and limit prolonged pre-activation times.
  • Monitoring: Kaiser test is negative on Pro; use chloranil test to assess coupling to Pro or proceed to a primary amine residue before Kaiser monitoring resumes.

• Applications

  • Synthesis of prolinamide-terminated peptides, proline-rich motifs (e.g., SH3-binding PXXP sequences), and libraries where a defined C-terminal Pro–NH2 is required (literature).

Reaction Conditions

• General Boc SPPS conditions on PAM resins (literature guidance; adjust per sequence and actual resin loading from CoA)

• Swelling and preparation

  • Swell resin 30–60 min in DCM, then exchange to DMF (3–5× washes). Maintain gentle agitation to avoid bead attrition.

• Boc deprotection

  • Reagent: 50% TFA in DCM (or neat TFA). Typical regimen: 2×5–10 min treatments at rt. Thorough DMF/DCM washes after deprotection. Neutralize with 10–20% DIEA in DCM or DMF, 2×5 min.

• Coupling

  • Common systems: DIC (3–5 eq) + Oxyma/HOBt (3–5 eq) or HBTU/HATU (3–5 eq) + base (DIEA, 4–6 eq).
  • Solvent: DMF or NMP; DCM/DCE may help hydrophobic residues. Typical coupling time: 30–90 min at rt. For difficult steps or to Pro, consider double coupling or overnight reaction.
  • Monitoring: Chloranil test for secondary amines; Kaiser test for primary amines.

• Capping

  • 5–10% Ac2O + DIEA in DMF (or DCM), 5–10 min, to cap unreacted amines after each coupling.

• Final cleavage/deprotection (PAM)

  • Cleavage: Anhydrous HF (0 °C, 30–60 min) with scavengers (e.g., anisole, thioanisole, cresol, EDT) depending on side-chain protections. Strict HF safety protocols required.
  • Workup: Evaporate HF, wash resin, precipitate peptide from TFA solution into cold ether, and purify (e.g., RP-HPLC) as needed.

• Expected outcomes

  • Peptides obtained as C-terminal amides. Yields depend on sequence length/complexity and resin loading; consult literature precedents for analogous sequences.

Safety and Handling

• Item-specific safety data (from Product Data)

  • GHS Classification / Signal Word / H-Statements / Pictograms: Not specified for this item; refer to SDS.
  • Storage: Store at 2–8 °C (Product Data). Shipments are on wet ice.

• General handling guidance (defer to SDS for authoritative instructions)

  • Personal protective equipment: Lab coat, safety glasses, and suitable gloves (e.g., nitrile). Use in a fume hood when handling coupling reagents, acids, or bases associated with SPPS.
  • Dust control: Avoid creating dust; polymer beads can generate nuisance dust. Use gentle vacuum/filtration and anti-static measures.
  • Incompatibilities: Keep dry and away from strong oxidizers. Avoid prolonged exposure to strong acids/bases outside standard SPPS protocols which may degrade linker or polymer (general).
  • Moisture/solvent management: Store dry and closed. Many SPPS steps use DMF/DCM—ensure adequate ventilation; prevent solvent-laden waste buildup.
  • Special risks related to downstream use: Final cleavage of PAM resins typically employs anhydrous HF or HF-generating systems; these procedures are extremely hazardous and must be carried out only in properly engineered apparatus by trained personnel with HF protocols, PPE, calcium gluconate gel availability, and dedicated waste handling (literature). This hazard pertains to usage steps, not to the resin as supplied.
  • First-aid overview: In case of exposure to associated solvents/reagents, rinse affected area with water and seek medical attention. For HF exposure risks during cleavage work, follow institutional HF emergency procedures. Always consult the SDS of this product and all reagents employed in SPPS.

Solvent Selection

• Applicability: This is a solid-phase support; solvent selection concerns swelling, diffusion, and compatibility with Boc SPPS.

• General/literature solvent behavior of PS/PAM resins

  • Strong swelling: DCM, DCE, DMF, NMP, toluene, THF.
  • Moderate/variable swelling: CHCl3, EtOAc (sequence- and crosslinking-dependent).
  • Poor/limited: Alcohols (MeOH/EtOH) and nonpolar alkanes (hexanes). Insoluble in water; minimal swelling in aqueous media.

• Choosing solvents by step (general)

  • Swelling/equilibration: Begin with DCM or DMF (or DCM→DMF exchange) for efficient bead expansion.
  • Boc deprotection: TFA in DCM or neat TFA is standard; follow by neutralization (e.g., DIEA in DCM/DMF) and thorough washes.
  • Coupling: DMF or NMP are common; DCM or DCE may be beneficial for hydrophobic sequences. Reagent systems include DIC/HOBt, DIC/Oxyma, HBTU/HOBt, HATU/Oxyma (literature). Maintain good swelling for Pro-containing sequences.
  • Capping: Ac2O/DIEA in DMF or DCM to cap unreacted amines.

• Practical tips

  • Always pre-swell in your chosen solvent before measuring bed volume and starting cycles.
  • When minimizing chlorinated solvents, DMF or NMP alone can be used, but confirm acceptable swelling; consider greener DMF replacements where validated.
  • Thorough solvent exchanges between steps reduce carryover of acids/bases and improve coupling efficiency.

Storage and Reconstitution

• Item-specific storage (from Product Data)

  • Store at 2–8 °C in a tightly closed container. Avoid moisture ingress. Shipped on wet ice.

• General handling/pre-use (literature guidance)

  • Upon receipt, allow the container to equilibrate to room temperature in a desiccated environment before opening to minimize condensation.
  • If supplied solvent-wet, keep the container well sealed; if dry, store with desiccant. Do not freeze.
  • Record net weight and, if known from CoA, resin loading to plan stoichiometry. If loading is unknown, determine experimentally before scale-up.

• Reconstitution/conditioning for use

  • Pre-swell the resin in an appropriate solvent (e.g., DCM 30 min) and exchange to the synthesis solvent (e.g., DMF) with multiple washes to ensure full swelling and removal of storage media.
  • Prior to HF cleavage, dry the resin thoroughly (vacuum, solvent exchange to DCM, then dry) to minimize entrained water and improve cleavage efficiency.

• Stability

  • Stable for extended periods at 2–8 °C under dry, dark conditions. Avoid prolonged exposure to strong acids/bases or elevated temperatures outside normal SPPS steps, which can degrade the linker or polymer backbone.

• Documentation

  • For exact shelf life, residual solvents, and any stabilizers, Not specified for this item; refer to CoA/Spec Sheet.

Structure and Identity

• Item-specific identifiers (from Product Data)

  • SKU: B476082
  • Product Name: Boc-Pro-PAM resin
  • CAS: Not specified for this item; refer to CoA/Spec Sheet.
  • SMILES / InChIKey: Not applicable for macromolecular polymeric resins; not specified for this item.
  • Molecular Formula: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet.

• Structural description (general/literature)

  • Resin type: Solid-phase peptide synthesis (SPPS) resin built on a polystyrene (PS) matrix crosslinked (typically with DVB) and bearing a phenylacetamidomethyl (PAM) linker.
  • Loading: Preloaded with Nα-Boc-L-proline at the linker terminus (Boc-Pro–PAM–PS). The peptide grows from the N-terminus of Pro.
  • Cleavage outcome: PAM linker is acid-labile to anhydrous HF (or HF-equivalents), furnishing a peptide with a C-terminal amide. Thus, this resin yields C-terminal prolinamide peptides after global deprotection/cleavage (literature).
  • Functional groups present: tert-Butoxycarbonyl (Boc) protecting group on proline’s secondary amine; amide linkage to the PAM benzylic handle; aromatic phenyl and polymeric styrene backbone.
  • Stereochemistry: L-Proline, five-membered pyrrolidine ring with fixed L-configuration at the α-carbon (literature). Proline’s secondary amine influences coupling monitoring methods.

• 2D structure in words (general/literature)

  • A crosslinked polystyrene bead supports a benzylic –CH2–Ph–CO–NH–CH2– (PAM) linker terminating in an amide bond to the C-terminus of L-proline; the N-terminus carries a Boc group ready for iterative Boc SPPS cycles.

Synthetic Utility

• Core utility (general/literature)

  • Provides a robust solid support for Boc-based SPPS of peptides ending in C-terminal prolinamide. The secondary amine of Pro and the PAM linker characteristics dictate specific monitoring and coupling strategies.

• Functional group and linker reactivity

  • Nα-Boc protection: Removable with TFA to reveal the proline secondary amine for subsequent coupling.
  • PAM linker: Benzylic amide linkage stable to TFA and bases used during chain assembly; cleavable with HF to yield –CONH2 terminus.

• Strategic use cases

  • Libraries or sequences requiring a fixed C-terminal Pro–NH2 (e.g., SH3-binding motifs, proline-rich cell-penetrating fragments).
  • Sequences sensitive to C-terminal carboxylate; amide improves stability/neutrality and can impact bioassays (general observation).

• Practical guidance

  • Activation systems: DIC/Oxyma or DIC/HOBt are effective with minimal racemization. Uronium reagents (HBTU/HATU) in DMF/NMP are also common.
  • Monitoring: Use chloranil test during coupling to Pro; Kaiser test resumes utility after installing a primary amine residue.
  • Aggregation management: If sequence aggregation occurs, consider lower substitution resins (per CoA) or incorporate pseudo-prolines/chaotropic co-solvents; double couplings and longer times frequently help.
  • Protecting groups: Select side-chain protections compatible with HF cleavage (Boc/tBu/Bzl families typical in Boc chemistry).

Target Specificity

• Not applicable. This product is a chemical solid-phase support, not a biological targeting reagent (e.g., antibody, ligand, or probe). No antigen/epitope or species reactivity is relevant.