Source: https://guthlabs.ai/docs/instruments/enzyme-inhibition-type-comparator/mechanism/

instrument mechanism / verified-clean

# Enzyme Inhibition Type Comparator mechanism

The inspectable method record for Enzyme Inhibition Type Comparator, kept separate from implementation and qualification.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Model scope

The listed formulas are too abbreviated to verify uniquely. Under the conventional interpretation used in the test vectors, competitive inhibition raises apparent Km without changing Vmax, uncompetitive inhibition lowers both Vmax and Km by the same alpha factor, and pure noncompetitive inhibition lowers Vmax without changing Km. The instrument should document these equations, add substrate concentrations as an input or plotting-grid specification, define the noncompetitive convention, and validate all parameter domains before release.

- The specification does not state the actual modified Michaelis-Menten equations, so correctness cannot be verified from the description alone.

- The substrate concentration [S] is missing from the listed inputs even though it is required to generate a velocity curve and sampled plot points.

- The term noncompetitive is ambiguous: the standard pure-noncompetitive model has unchanged Km and reduced Vmax, whereas mixed inhibition has both Km and Vmax altered. The instrument must explicitly choose pure noncompetitive or support separate mixed-inhibition constants.

- A single Ki term per inhibition type assumes the relevant inhibitor dissociation constants are known and sufficient; for mixed inhibition, separate Ki for free enzyme and Ki-prime for enzyme-substrate complex are generally required.

- The comparison curve should explicitly include the uninhibited equation v=Vmax[S]/(Km+[S]) and identify whether plotted outputs are initial rates.

## Units and conventions

- Vmax is in a velocity unit, such as concentration per time.

- Km, Ki, inhibitor concentration [I], and substrate concentrations [S] must use the same concentration unit.

- The vectors below use Vmax=100 velocity units, Km=10 concentration units, Ki=5 concentration units, and [I]=5 concentration units unless otherwise stated.

- The calculations assume the conventional idealized single-inhibitor model with alpha=1+[I]/Ki: competitive v=Vmax[S]/(alpha Km+[S]); uncompetitive v=Vmax[S]/(Km+alpha[S]); pure noncompetitive v=(Vmax/alpha)[S]/(Km+[S]).

- The uninhibited comparison is v0=Vmax[S]/(Km+[S]).

## Inspectable vector

One of 4 source-bound review vectors:

````
{
  "inputs": {
    "Vmax": 100,
    "Km": 10,
    "Ki": 5,
    "I": 5,
    "inhibition_type": "competitive",
    "substrate_concentrations": [
      0,
      10,
      100
    ]
  },
  "expected_outputs": {
    "alpha": 2,
    "apparent_Vmax": 100,
    "apparent_Km": 20,
    "inhibited_velocity": [
      0,
      33.3333333333,
      83.3333333333
    ],
    "uninhibited_velocity": [
      0,
      50,
      90.9090909091
    ],
    "curve_features": {
      "inhibited_root": [
        0
      ],
      "uninhibited_root": [
        0
      ],
      "inhibited_horizontal_asymptote": 100,
      "uninhibited_horizontal_asymptote": 100,
      "inhibited_extrema": "none for S>=0",
      "uninhibited_extrema": "none for S>=0"
    }
  },
  "working": "alpha=1+[I]/Ki=1+5/5=2. Competitive equation: v=100S/(2*10+S)=100S/(20+S). At S=0: v=100*0/(20+0)=0. At S=10: v=100*10/(20+10)=1000/30=33.3333333333. At S=100: v=100*100/(20+100)=10000/120=83.3333333333. Apparent parameters: Vmax,app=100 and Km,app=alpha*Km=2*10=20. Uninhibited equation: v0=100S/(10+S). At S=0: 0. At S=10: 1000/20=50. At S=100: 10000/110=90.9090909091. The root is S=0 and the horizontal asymptote is Vmax=100."
}
````

## Failure boundary

**BREAK_CLAIMED** · SELF_FLAGGED

The model has an undefined-result failure at Ki=0 with nonzero inhibitor concentration, and it also needs explicit validation for negative concentrations. Without validation, a negative inhibitor concentration can yield a mathematically valid but physically inappropriate result.

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/enzyme-inhibition-type-comparator/>)[03**Implementation**](<https://guthlabs.ai/docs/instruments/enzyme-inhibition-type-comparator/implementation/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/enzyme-inhibition-type-comparator/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche6/tranche6-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`