## 4 Discussion  
[PERSON] and [PERSON] observed that the DNA/mRNA complementary sequence (A- \(>\) T, T- \(>\) A, G- \(>\) C, C- \(>\) G) can be a viable source of amino acid sequences which bind to the collagen type I protein [36]. Their study demonstrated the complementary residues 772-778 for the COL1A2 gene, which encodes collagen type I alpha unit 2 in humans, is a peptide which binds to collagen type I. The collagen amino acid sequence is GPQCLLG. The complementary amino acid sequence is TKKTLRT. The authors then compared the hydropathy trend of TKKTLRT with SSNTLRS (analogous sequence in mouse) and SQNPVQP (fibroblast collagenase sequence) using the Kyte-Doolittle hydropathy scale, and they showed a strong similarity of profiles. In studying the hydropathy plots of COL1A2 sense peptide (TKKTLRT), collagenase peptide (SQNPVQP), and collagen type I chain \(\alpha_{2}\) (GPQGLLG), we noticed trends in the hydropathy curves between the sequences. The TKKTLRT and SQNPVQP have similar trends in hydropathy plots in the Wimley-White scale and nearly identical hydropathy plots for the Kyte-Doolittle scale. The de Souza paper showed a similar strength of interaction between collagen and TKKTLRT and SQNPVQP through radioactively labeling collagen and quantifying the dose-dependent inhibition of gamma radiation for each peptide. Studies have explored sense-antisense peptide interactions in many protein contexts. In HIV research, [PERSON] et al. recognized the sense-antisense interactions that underlie the relationship between HIV glycoproteins and the host cell HIV receptors [43]. This hypothesis has also been tested for a ribonuclease S-peptide using analytical chromatographic affinity experiments, which concluded that there is evidence for antisense peptide binding [44]. A recent review estimates that such peptide pairings have been experimentally confirmed in more than 50 separate systems [34]. Recent progress has also shown evidence  
Figure 8: Streptavidin-coated quantum dot labelling of biotinylated peptides on type I collagen. The Q-dots complexed with biotinylated peptides remained on collagen after washing. The corresponding summed pixel intensities are provided in the bar chart. The predicted peptide TKKTLRT resulted in the highest coverage based on the quantum dots assay. that tRNA, which pair with mRNA in the translation process, holds structural information about the attached amino acid that is additional to the standard codon table [45]. New models of the information contained within the standard genetic code through previously unstudied symmetries have recently been proposed [46; 47; 48]. While it is unclear how much information the biological machinery contains, the method of identifying generative relationships between nucleic acid sequences and protein sequences can be applied to the small-codon-like segments of peptides and proteins to begin to see rules which describe the binding properties of peptide and protein sequences. To evaluate this hypothesis further in the context of collagen-binding peptides, we developed a screening method using hydropathy for identifying likely binding sites for collagen using three consecutive amino acid segments, in parallel to codons within nucleic acid sequences. Collagen-binding peptides hold promise for advanced technologies in materials science and in medical treatments. A recent study has shown that collagen-binding peptides can be molecular-level markers for mechanical damage in collagen, which is applicable to assessing the integrity of collagen within a system [49]. The mechanical properties of collagen are not just being characterized by computational approaches. Much progress is being made in understanding the toughening mechanisms in collagen systems and how to build bioinspired materials with bottom-up approaches [50; 51]. The interfacial challenges in these materials are often multi-dimensional and interdependent on several environmental factors.