{
  "abstract": "Active-site pre-organisation is a well-characterised contributor to enzyme catalysis, and progressive rigidification of catalytic residues during HG-series Kemp eliminase evolution — including decreasing structure-normalised B-factor Z-scores at the position-50 residue — has already been reported directly from room-temperature crystallography (Broom et al., 2020). The contribution here is therefore not that observation, but a bounded quantitative test of how completely a single compact scalar recovers catalytic-efficiency ordering within an HG Kemp eliminase series, together with an explicit account of where that scalar fails to transfer. In the primary HG dataset — five room-temperature structures from the directed-evolution series plus the separately engineered variant HG4 — the residue-50 side-chain scalar correlated with log10(kcat/KM) at r = −0.9899 (p = 1.52 × 10-4) and reproduced the catalytic-efficiency ordering of the archived scalar values exactly (Spearman ρ = −1.000; exact two-sided permutation p = 0.0028). Restricting the analysis to the five evolutionary-series variants gave r = −0.9893. The association is robust to the choice of published kinetic dataset. In four independently designed HG variants the multi-residue active-site scalar was directionally negative (r = −0.7759) but weak on a rank basis (ρ = −0.400; exact two-sided p = 0.75) and is treated as neither replication nor support of comparable weight. Application of the same extraction logic to an independent KE07 scaffold failed a pre-committed robustness criterion and is reported as a negative transfer result. Two distinct sensitivities are separated there: a normalization correction, and an additional dependence on which deposited structure represents each variant across all 48 pre-declared combinations. We do not claim that the specificity of the primary single-residue scalar has been established: the archived negative controls were computed on a four-residue active-site average, not on the primary scalar, and their generating workflow is not fully archived. B-factors are treated throughout as operational crystallographic observables rather than as measurements of solution dynamics. The result is a narrowly scoped, reproducible descriptive reanalysis of public data with a clearly documented limit on transfer — not a causal mechanism, a specificity demonstration, or a generalisation to other reaction classes.",
  "abstract_shown": true,
  "affiliations": [
    "founder, GreenFelix Innovations Pvt. Ltd., balco nagar , Korba, Chhattisgarh, India",
    "internal medicine , BALCO Hospital, balco nagar ,korba, Korba, Chhattisgarh, India"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 1,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Mahesh babu Sodalagunta"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6a8pnnt7jdkt7.bib",
  "cited_by": 0,
  "doi": "10.26434/chemrxiv.15008941/v1",
  "fulltext_url": null,
  "id": "6a8pnnt7jdkt7",
  "issns": [],
  "landing_url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008941/v1",
  "language": null,
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2505|Enzyme Structure and Function"
    ]
  ],
  "openalex": "W7213464345",
  "pdf_url": "https://chemrxiv.org/doi/pdf/10.26434/chemrxiv.15008941/v1",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-16",
  "publisher": "American Chemical Society (ACS)",
  "ris": "https://research.draconitic.com/paper/6a8pnnt7jdkt7.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:19Z",
      "native_id": "10.26434/chemrxiv.15008941",
      "source": "chemrxiv",
      "url": "https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008941/v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:2505|Enzyme Structure and Function",
      "subfield": "materials-polymers"
    }
  ],
  "title": "A residue-50 crystallographic B-factor scalar tracks catalytic-efficiency ordering across HG Kemp eliminase evolution",
  "title_text": "A residue-50 crystallographic B-factor scalar tracks catalytic-efficiency ordering across HG Kemp eliminase evolution",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:19Z",
  "url": "https://research.draconitic.com/paper/6a8pnnt7jdkt7",
  "venue": "ChemRxiv",
  "versions": []
}