Collagen I, alpha chain (98-110) (33-12-7) Physical and Chemical Properties
Collagen I, alpha chain (98-110)
Synthetic collagen‑derived peptide (residues 98–110) provided as a lyophilized fragment for assay development, enzymology studies and peptide R&D.
| CAS Number | 33-12-7 |
| Family | Collagen-derived peptides |
| Typical Form | Lyophilized powder |
| Common Grades | EP |
Collagen I, alpha chain (98–110) is a synthetic peptide fragment derived from the N-terminal region of the type I collagen α-chain. Structurally it is a short collagen-derived peptide with a Gly–X–Y motif characteristic of collagen sequences; the reported sequence is Gly–Leu–Hyp–Gly–Nle–Lys–Gly–His–Arg–Gly–Phe–Ser–Gly. The presence of hydroxyproline (Hyp) and a high glycine content are consistent with collagen-mimetic local structure, while inclusion of basic residues (Lys, Arg, His) and a hydrophobic residue surrogate (norleucine, Nle) create a mixed polar–apolar side-chain pattern that governs both enzyme recognition and aqueous behaviour.
Electronically and physicochemically this peptide is highly polar and hydrogen-bonding rich: computed descriptors indicate a very large topological polar surface area and numerous hydrogen-bond donors and acceptors. The calculated partitioning descriptor (XLogP) is strongly negative, consistent with low lipophilicity and high water solubility under typical aqueous conditions. The peptide is flexible (many rotatable bonds) and of sufficient size and conformational freedom that routine small-molecule conformer generation is not feasible; this flexibility and the dense pattern of polar residues also favour interaction with collagen-processing enzymes and chaperones rather than passive membrane permeation.
Functionally, this sequence is used as a synthetic substrate for human protocollagen lysyl hydroxylase in biochemical assays; radiolabeled (tritium) variants of the peptide are reported for mechanistic and enzymatic studies, which is reflected in isotope labelling noted for some material. The peptide’s biophysical attributes and its enzymatic substrate role underlie its application in studies of collagen post-translational modification and enzyme kinetics. Common commercial grades reported for this substance include: EP.
Molecular Overview
Molecular Weight and Composition
- Molecular formula: \(C_{57}H_{91}N_{19}O_{16}\).
- Molecular weight: 1302.5 (reported numeric value).
- Exact mass / Monoisotopic mass: 1301.70556639 (reported numeric value).
- Heavy atom count: 92.
- Isotope atom count: 2.
- Sequence (reported): Gly-Leu-Hyp-Gly-Nle-Lys-Gly-His-Arg-Gly-Phe-Ser-Gly.
These values indicate a medium-length peptide (molecular mass ~1.3 kDa) with a composition typical of collagen-derived fragments: frequent glycine residues, hydroxylated proline, basic side chains, and a mix of polar and hydrophobic side chains. The indicated isotope count of two is consistent with laboratory isotopic labelling in some preparations.
Charge, Polarity, and LogP
- Formal computed charge: \(0\).
- XLogP3-AA (computed): \(-5.1\).
- Topological polar surface area (TPSA): \(557\).
- Hydrogen-bond donor count: \(18\).
- Hydrogen-bond acceptor count: \(21\).
- Rotatable bond count: \(44\).
The computed formal charge of \(0\) reflects the neutral specification used for descriptor calculation; however, the primary structure contains multiple ionizable side chains (Lys, Arg, His) plus free N- and C-termini in typical synthetic preparations, so the solution-phase net charge is pH-dependent and will often be positive at physiological pH. The very large TPSA together with the large numbers of hydrogen-bond donors and acceptors and the strongly negative XLogP indicate dominant aqueous solubility, pronounced polarity, and poor passive membrane permeability. A high rotatable-bond count denotes extensive conformational freedom, which is relevant to folding, enzyme recognition, and analytical handling.
Biochemical Classification
This substance is a collagen-derived peptide fragment (residues 98–110 of type I collagen α-chain) and is classified functionally as a synthetic enzymatic substrate for protocollagen lysyl hydroxylase. It is a linear, covalently-bonded peptide unit (covalently-bonded unit count: 1) and contains multiple defined stereocenters consistent with L-amino-acid stereochemistry. Conformer generation for three-dimensional modelling is not practical for routine small-molecule conformer tools because of the peptide’s size and conformational flexibility; appropriate modelling requires peptide/protein-level methods.
Chemical Behavior
Stability and Degradation
As a peptide, the fragment shows the general stability profile of unprotected linear peptides: it is chemically labile to prolonged exposure to strong acids or bases and is susceptible to hydrolytic cleavage under extreme pH and temperature. Enzymatically, it is expected to be susceptible to proteolytic degradation by endopeptidases and exopeptidases in biological matrices; the presence of hydroxyproline can locally stabilise collagen-like conformations but does not confer substantial resistance to proteases. The substitution of norleucine (Nle) in place of methionine reduces vulnerability to sulfur oxidation compared with methionine-containing analogues. High polarity and multiple hydrogen-bonding sites favour solvation in water and aqueous buffers; aggregation is unlikely at typical assay concentrations but may occur at very high concentration or under conditions that reduce solvation.
Hydrolysis and Transformations
Primary chemical transformations are hydrolytic cleavage to component amino acids and peptidic fragments. Under biological conditions the peptide can undergo enzymatic modifications relevant to collagen biochemistry, such as lysine hydroxylation by lysyl hydroxylases when used as a substrate in vitro. Other potential transformations include deamidation of Asn/Gln residues (if present), racemization under harsh conditions, and, for labeled material, isotope dilution or exchange under strong reducing/oxidizing conditions. Because some preparations are supplied with tritium labelling, isotope handling and radiolytic stability should be considered during storage and disposal; the reported isotope atom count is \(2\), indicating isotopic modification in certain samples.
Biological Role
Functional Role and Pathways
This peptide functions as a synthetic substrate for protocollagen lysyl hydroxylase, the enzyme responsible for post-translational hydroxylation of lysine residues in procollagen. Lysyl hydroxylation is a critical modification in collagen biosynthesis that influences subsequent glycosylation and cross-linking pathways and thereby affects fibril formation and mechanical properties of the extracellular matrix. In biochemical assays the peptide provides a defined minimal substrate for kinetic and mechanistic studies of lysyl hydroxylase activity and can be used to map enzyme specificity and inhibitor effects.
Physiological and Cellular Context
Residues 98–110 originate from the collagen I α-chain and reflect sequence motifs encountered during biosynthesis and folding of procollagen in the endoplasmic reticulum. In vivo, comparable sequences are part of a larger triple-helical domain that interacts with molecular chaperones and modifying enzymes; as a short fragment, this peptide is primarily useful as a probe of enzyme–substrate interactions rather than as a structural mimic of the full triple helix. In cell-free assays it models a local sequence environment for lysyl hydroxylase action; in cellular contexts, the full-length procollagen polypeptide and its assembly into triple helices determine physiological processing.
Identifiers and Synonyms
Registry Numbers and Codes
- CAS number: 33-12-7 (provided registry identifier).
- InChIKey: LZCXUJHSTWYBEA-FUYNMKNISA-N
- InChI: InChI=1S/C57H91N19O16/c1-4-5-14-38(70-45(80)26-67-51(86)39-22-35(78)25-64-39)53(88)74-36(15-9-10-17-58)49(84)65-28-47(82)72-41(21-34-24-62-31-69-34)55(90)75-37(16-11-18-63-57(60)61)50(85)66-27-46(81)71-40(20-33-12-7-6-8-13-33)54(89)76-43(30-77)52(87)68-29-48(83)92-56(91)42(19-32(2)3)73-44(79)23-59/h6-8,12-13,24,31-32,34-43,64,77-78H,4-5,9-11,14-23,25-30,58-59H2,1-3H3,(H,65,84)(H,66,85)(H,67,86)(H,68,87)(H,70,80)(H,71,81)(H,72,82)(H,73,79)(H,74,88)(H,75,90)(H,76,89)(H4,60,61,63)/t34?,35-,36+,37+,38+,39+,40+,41+,42+,43+/m1/s1/i10T,17T/t10?,17?,34?,35-,36+,37+,38+,39+,40+,41+,42+,43+
- SMILES: [3H]C(CCC@@HNC(=O)C@HNC(=O)CNC(=O)[C@@H]3CC@HO)C([3H])N
(Identifiers above are provided as reported for this substance.)
Synonyms and Biological Names
- collagen I, alpha chain (98-110)
- Gly-Leu-Hyp-Gly-Nle-Lys-Gly-His-Arg-Gly-Phe-Ser-Gly
- Collagen I, alpha chain (98-110)
- Gly-leu-hyp-gly-nle-lys-gly-his-arg-gly-phe-ser-gly
- RefChem:918925
These names and sequence descriptors are used interchangeably in biological and biochemical contexts to denote the same peptide fragment and its common shorthand sequence representation.
Safety and Handling Overview
Handling and Storage of Biochemical Materials
This peptide is a nonvolatile, water-soluble biochemical reagent. General safe-handling principles for peptides and synthetic biochemical substrates apply: use appropriate personal protective equipment (gloves, lab coat, eye protection); avoid inhalation of powders and contact with mucous membranes; control dust generation during handling of lyophilized material. Store dry, protected from moisture and proteolytic contamination; many laboratories store synthetic peptides lyophilized at low temperature and reconstitute immediately before use to minimise degradation and freeze–thaw cycles. For radiolabeled variants (e.g., tritium-labelled material) follow institutional radiation safety procedures and local regulations for storage, handling, and disposal. For detailed hazard, transport and regulatory information, users should refer to the product-specific Safety Data Sheet (SDS) and local legislation.
