/brenda-database

name: "brenda-database"
description: "BRENDA Enzyme DB SOAP/REST queries: kinetic parameters (Km, Vmax, kcat, Ki), EC classes, substrate specificity, inhibitors, cofactors, organism data. 80K+ enzymes, 7M+ values. Free academic registration. For metabolic modeling use cobrapy-metabolic-modeling; metabolites use hmdb-database."
license: "CC-BY-4.0"

BRENDA Enzyme Database

Overview

BRENDA (BRaunschweig ENzyme DAtabase) is the world's most comprehensive enzyme information system, containing 80,000+ enzyme entries covering all classified enzymes (EC numbers). It holds 7M+ experimentally measured kinetic parameters (Km, Vmax, kcat, Ki, inhibition constants), substrate specificity data, cofactor requirements, tissue expression, and organism-specific enzyme variants from 200,000+ literature references. Programmatic access is via a SOAP-based web service (Python zeep library) with free academic registration.

When to Use

• Retrieving kinetic parameters (Km, kcat, Vmax, Ki) for a specific enzyme and substrate combination
• Comparing kinetic parameters across organisms or mutant variants for an enzyme
• Finding natural substrates, inhibitors, and cofactors for an EC number
• Building kinetic models for metabolic simulations requiring Michaelis-Menten parameters
• Identifying enzyme-specific structural data (recommended pH, temperature optima)
• Cross-referencing EC numbers with UniProt accessions and organism taxonomy
• For metabolic network simulation use `cobrapy-metabolic-modeling`; for metabolite structures use `hmdb-database`

Prerequisites

• **Python packages**: `zeep` (SOAP client), `pandas`, `requests`
• **Data requirements**: EC numbers (e.g., `1.1.1.1`), enzyme names, or organism names
• **Environment**: internet connection; free academic registration at https://www.brenda-enzymes.org/register.php
• **Rate limits**: no explicit limit stated; avoid bulk automated queries; space requests with sleep

pip install zeep pandas requests
# Register at https://www.brenda-enzymes.org/register.php to obtain API credentials

Quick Start

from zeep import Client

WSDL = "https://www.brenda-enzymes.org/soap/brenda_zeep.wsdl"
client = Client(WSDL)

EMAIL = "your@email.com"
PASSWORD_SHA256 = "your_sha256_hashed_password"  # Use hashlib.sha256

# Get Km values for lactate dehydrogenase (EC 1.1.1.27) and pyruvate
ec_number = "1.1.1.27"
params = (EMAIL, PASSWORD_SHA256,
          f"ecNumber*{ec_number}", "substrate*pyruvate", "", "", "", "", "")
result = client.service.getKmValue(*params)
print(f"Km values for LDH with pyruvate: {len(result)} records")
for r in result[:3]:
    print(f"  Km={r.kmValue} {r.kmValueMaximum or ''} mM | org: {r.organism} | PMID: {r.literature}")

Core API

Query 1: Km Values for Enzyme-Substrate Pair

Retrieve Michaelis constant (Km) values for a specific enzyme and substrate.

from zeep import Client
import hashlib, pandas as pd

WSDL = "https://www.brenda-enzymes.org/soap/brenda_zeep.wsdl"
client = Client(WSDL)

EMAIL = "your@email.com"
PASSWORD = "your_password"
PASSWORD_SHA256 = hashlib.sha256(PASSWORD.encode()).hexdigest()

def get_km_values(ec_number, substrate=""):
    """Retrieve Km values for an EC number, optionally filtered by substrate."""
    substrate_param = f"substrate*{substrate}" if substrate else ""
    params = (EMAIL, PASSWORD_SHA256,
              f"ecNumber*{ec_number}", substrate_param, "", "", "", "", "")
    return client.service.getKmValue(*params)

# Km for glucokinase (EC 2.7.1.2) with glucose
results = get_km_values("2.7.1.2", substrate="glucose")
print(f"Km (glucose, glucokinase): {len(results)} measurements")

rows = []
for r in results[:10]:
    rows.append({
        "km_value": r.kmValue,
        "km_max": r.kmValueMaximum,
        "unit": "mM",
        "organism": r.organism,
        "commentary": r.commentary[:80] if r.commentary else "",
        "pmid": r.literature,
    })
df = pd.DataFrame(rows)
print(df.to_string(index=False))

# Get ALL Km values (all substrates) for an EC number
all_km = get_km_values("1.1.1.1")  # Alcohol dehydrogenase
print(f"\nAlcohol dehydrogenase - total Km records: {len(all_km)}")
substrate_counts = {}
for r in all_km:
    sub = r.substrate or "unknown"
    substrate_counts[sub] = substrate_counts.get(sub, 0) + 1
top_substrates = sorted(substrate_counts.items(), key=lambda x: -x[1])[:5]
print("Top substrates by measurement count:")
for sub, cnt in top_substrates:
    print(f"  {sub}: {cnt} measurements")

Query 2: kcat (Turnover Number) Values

Retrieve catalytic rate constants (kcat) for an enzyme.

from zeep import Client
import hashlib, pandas as pd

WSDL = "https://www.brenda-enzymes.org/soap/brenda_zeep.wsdl"
client = Client(WSDL)

EMAIL = "your@email.com"
PASSWORD_SHA256 = hashlib.sha256("your_password".encode()).hexdigest()

def get_kcat_values(ec_number, substrate=""):
    substrate_param = f"substrate*{substrate}" if substrate else ""
    params = (EMAIL, PASSWORD_SHA256,
              f"ecNumber*{ec_number}", substrate_param, "", "", "", "", "")
    return client.service.getTurnoverNumber(*params)

results = get_kcat_values("1.1.1.27")  # Lactate dehydrogenase
print(f"kcat records for LDH: {len(results)}")

rows = []
for r in results[:10]:
    rows.append({
        "kcat": r.turnoverNumber,
        "unit": "1/s",
        "substrate": r.substrate,
        "organism": r.organism,
    })
df = pd.DataFrame(rows)
print(df.head())

Query 3: Substrates and Products

Retrieve natural substrates and products for an enzyme.

from zeep import Client
import hashlib, pandas as pd

WSDL = "https://www.brenda-enzymes.org/soap/brenda_zeep.wsdl"
client = Client(WSDL)

EMAIL = "your@email.com"
PASSWORD_SHA256 = hashlib.sha256("your_password".encode()).hexdigest()

def get_substrates_products(ec_number):
    params = (EMAIL, PASSWORD_SHA256,
              f"ecNumber*{ec_number}", "", "", "", "", "", "")