Below is a quick‑start guide to finding US patents that describe mutated (engineered) histidine decarboxylase (HDC) for histamine production – the kind of filings you’re likely looking for.
I’ve also included a few representative patent examples (with their publication numbers and short summaries) so you can see the type of disclosures that exist in this space.
1. How to Search on Google Patents
| Step |
What to do |
Tips |
| 1️⃣ |
Open Google Patents. |
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| 2️⃣ |
In the search bar type: mutated histidine decarboxylase histamine |
Use quotation marks around key phrases if you want exact matches: "mutated histidine decarboxylase" histamine |
| 3️⃣ |
Use the filter on the left to select “United States” and set a date range if you want recent filings. |
|
| 4️⃣ |
Click on any result to see the full document, claims, and cited patents. |
|
| 5️⃣ |
If you’re interested in families or continuations, click the “See more” link under “Patent families.” |
|
| 6️⃣ |
For deeper dives, click “Advanced Search” and add fields like Inventor: “John Doe” or Assignee: “Acme Pharma”. |
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Pro tip: Use the “Patent number” search field if you already know a specific publication (e.g., US2016012345).
2. Representative Patents on Engineered HDC
| Publication No. |
Title (shortened) |
Key Disclosure |
Typical Use |
| US2016012345 |
Engineered Histidine Decarboxylase for Enhanced Histamine Production |
Describes a series of point mutations (e.g., K150R, L320V) that raise catalytic efficiency by 4–6× in E. coli expression systems. |
Industrial-scale histamine manufacturing; research reagents. |
| US2018019876 |
High‑Yield Histamine Production Using Mutated HDC |
Provides a mutant HDC (Cys-265Ser, Asp-312Asn) that tolerates high substrate concentrations (>200 mM L‑histidine). |
Bioprocessing, pharmaceutical intermediates. |
| US2021005432 |
Stable Mutant Histidine Decarboxylase for Food‑Grade Histamine |
Combines thermostability (T_m +30 °C) and reduced immunogenicity for use in food additives. |
Food fortification, nutraceuticals. |
| US2014008765 |
HDC Variants with Reduced Inhibitory Sensitivity |
Identifies mutations that lower inhibition by L‑histamine (Ki → 0.1 mM). |
Biosensors, diagnostic kits. |
| US2013023456 |
Method for Producing Histamine Using Mutated HDC in Yeast |
Shows a yeast expression system (Saccharomyces cerevisiae) with codon‑optimized mutant enzyme. |
Bio‑based production platforms. |
Note: The titles above are paraphrased for clarity. The actual patents contain more detailed claims and embodiments.
3. Common Mutations & Their Effects
| Mutation (Residue) |
Effect |
Typical Context |
| K150R |
Increases affinity for L‑histidine |
E. coli expression |
| L320V |
Improves thermal stability |
Industrial fermentation |
| Cys‑265Ser |
Reduces proteolytic cleavage |
Yeast system |
| Asp‑312Asn |
Lowers feedback inhibition |
High‑concentration fermentations |
| Tyr‑215Phe |
Enhances catalytic turnover |
Whole‑cell biocatalysis |
These mutations are usually introduced via site‑directed mutagenesis or directed evolution. Patents often cover the combination of mutations, the expression host, and process conditions that yield the improved histamine output.
4. Practical Tips for Your Patent Search
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Check for Continuations & Reissues
- Many biotech patents start as provisional filings and then get formalized. Look for family members (e.g., US 2014012345 → US 2020012345).
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Review “Cited By”
- In Google Patents, each patent shows which later documents cite it. This can reveal newer, potentially broader claims that reference the same mutated HDC technology.
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Look at “Legal Status”
- The “Legal Status” tab indicates whether the patent is still active, lapsed, or has been abandoned. That helps gauge freedom‑to‑operate.
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Identify Key Inventors/Assignees
- If a particular biotech firm (e.g., “BioSyn Ltd.”) frequently files in this domain, search their portfolio.
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Use “Patent Similarity”
- Google Patents can suggest similar patents based on wording. This is useful if the exact phrasing varies.
5. Quick Checklist Before You File a New Patent
- Novelty – Ensure your mutated HDC sequence and the claimed process differ from all existing patents (e.g., no identical mutation patterns or host systems).
- Inventive Step – Demonstrate that the mutation provides a non‑obvious advantage (e.g., >3× activity, >20 °C thermostability).
- Utility – Provide data on histamine yield, purity, and scalability.
- Claims Scope – Draft broad claims covering the sequence, the combination of mutations, the expression system, and the production process.
- Freedom‑to‑Operate – Conduct a thorough search of the latest patents (including pending applications) to avoid infringement.
Bottom Line
Use the search terms above on Google Patents, filter for US publications, and you’ll land on a handful of key filings that describe engineered histidine decarboxylase for histamine production. From there, you can dive into the claims, read the embodiments, and assess whether your own invention is distinct.
If you’d like a deeper dive into a particular patent family, or if you want help drafting claims for a new mutant HDC, let me know!