主條目:酶
輔因子(cofactor)[]
每一步驟酵素的作用機轉，解釋了生物學中的酵素如何作用。維生素和礦物質的作用原理就常常是酵素的輔因子。
| Pt and enzyme | |||
| name | Cofactor(輔因子 | 功用 | |
| Atom group binding covalently to Pt. ( being called prosthetic group(輔效基) in enzyme ) | Atom group binding non-covalently to Pt. ( being called coenzyme(輔酶) in enzyme ) | ||
| kinase | Mg2+ | Enzyme | |
| Catalase(過氧化氫酶 | Fe2+/Fe3+ | enzyme | |
| Myoglobin(肌紅素 | 一個Fe2+ | O2 carrier ( storage ) | |
| Hemoglobin(血紅素 | 四個Fe2+、heme | O2 carrier ( transporter ) | |
| flavoprotein | FMN(flavin mononucleoside) | e- carrier | |
| flavoprotein | FAD(flavin adenine dinucleotide) | e- carrier | |
| iron-sulfur pt. | iron and sulfur | e- carrier | |
| coenzyme Q (ETC中唯一非蛋白質者) | ubiquinone(Co Q)
(coenzyme Q) |
e- carrier | |
| cytochrome | Heme with Fe2+ | e- carrier | |
| cytochrome | 必有Fe | ||
| Cytaa3 | Cu | ||
| Monoamine oxidase
MAO
|
Vit B2 | enzyme | |
| dehydrogenase | VitB3
NADP+ or NAD+ |
enzyme | |
| AA decarboxylase
dopa decarboxylase 5HT decarboxylase |
Vit B6:
pyridoxine(吡) |
enzyme | |
| carboxylase(羧化酶)
(form C-C) |
Vit B1(thiamine as cofactor) | enzyme | |
| microsomal hydroxylase
=cytochrome P450 monooxgenase enzyme system細胞色素P450單氧化酵素系統 =mixed-function oxidase(MFO)
a flavoprotein =P450 reductase 和下面比起來較少，所以是速率決定步驟 |
1 FMN(flavin mononucleoside)+
1 FAD(flavin adenine dinucleotide) |
NADPH | enzyme |
| microsomal hydroxylase
=cytochrome P450 monooxgenase enzyme system細胞色素P450單氧化酵素系統 =mixed-function oxidase(MFO)
=P450 =CYP an oxidase an hemeprotein 和上面比起來較多，所以不是速率決定步驟 |
Heme with Fe2+ | enzyme | |
| Enzyme cofactors | ||
| Active forms | vitamins | TPP / ThDP (B1) |
| FMN, FAD (B2) | ||
| NAD+, NADH, NADP+, NADPH (B3) | ||
| Coenzyme A (B5) | ||
| PLP / P5P (B6) | ||
| Biotin (B7) | ||
| THFA / H4FA, DHFA / H2FA, MTHF(B9) | ||
| AdoCbl, MeCbl (B12) | ||
| Ascorbic Acid (C) | ||
| Phylloquinone (K1) | ||
| Menaquinone (K2) | ||
| Coenzyme F420 | ||
| non-vitamins | ATP · CTP | |
| SAMe | ||
| PAPS | ||
| GSH | ||
| Coenzyme B ·
Cofactor F430 · Coenzyme M · Coenzyme Q | ||
| Heme / Haem (A, B, C, O) | ||
| Lipoic Acid | ||
| Methanofuran | ||
| Molybdopterin/Molybdenum cofactor | ||
| PQQ | ||
| THB / BH4 | ||
| THMPT / H4MPT | ||
| minerals | Ca2+ · Cu2+ ·
Fe2+, Fe3+ · Mg2+ · Mn2+ · Mo · Ni2+ · Se · Zn2+ | |
| Base forms | vitamins: see vitamins | |
| M: NUT | cof, enz, met | noco, nuvi, sysi/epon, met |
Vitamins and derivatives[]
| Cofactor | Vitamin | Additional component | Chemical group(s) transferred | Distribution |
| Thiamine pyrophosphate | Thiamine (B1) | None | 2-carbon groups, α cleavage | Bacteria, archaea and eukaryotes |
| NAD+ and NADP+ | Niacin (B3) | ADP | Electrons | Bacteria, archaea and eukaryotes |
| Pyridoxal phosphate | Pyridoxine (B6) | None | Amino and carboxyl groups(西101) | Bacteria, archaea and eukaryotes |
| Lipoamide | Lipoic acid | None | electrons, acyl groups | Bacteria, archaea and eukaryotes |
| Methylcobalamin | Vitamin B12 | Methyl group | acyl groups | Bacteria, archaea and eukaryotes |
| Cobalamine | Cobalamine (B12) | None | hydrogen, alkyl groups | Bacteria, archaea and eukaryotes |
| Biotin | Biotin (H) | None | CO2 | Bacteria, archaea and eukaryotes |
| Coenzyme A | Pantothenic acid (B5) | ADP | Acetyl group and other acyl groups | Bacteria, archaea and eukaryotes |
| Tetrahydrofolic acid | Folic acid (B9) | Glutamate residues | Methyl, formyl, methylene and formimino groups | Bacteria, archaea and eukaryotes |
| Menaquinone | Vitamin K | None | Carbonyl group and electrons | Bacteria, archaea and eukaryotes |
| Ascorbic acid | Vitamin C | None | Electrons | Bacteria, archaea and eukaryotes |
| Flavin mononucleotide | Riboflavin (B2) | None | Electrons | Bacteria, archaea and eukaryotes |
| Flavin adenine dinucleotide | Riboflavin (B2) | None | Electrons | Bacteria, archaea and eukaryotes |
| Coenzyme F420 | Riboflavin (B2) | Amino acids | Electrons | Methanogens and some bacteria |
Non-vitamins[]
| Cofactor | Chemical group(s) transferred | Distribution |
| Adenosine triphosphate | Phosphate group | Bacteria, archaea and eukaryotes |
| S-Adenosyl methionine | Methyl group | Bacteria, archaea and eukaryotes |
| Coenzyme B | Electrons | Methanogens |
| Coenzyme M | Methyl group | Methanogens |
| Coenzyme Q | Electrons | Bacteria, archaea and eukaryotes |
| Cytidine triphosphate | Diacylglycerols and lipid head groups | Bacteria, archaea and eukaryotes |
| Glutathione | Electrons | Some bacteria and most eukaryotes |
| Heme | Electrons | Bacteria, archaea and eukaryotes |
| Methanofuran | Formyl group | Methanogens |
| Molybdopterin | Oxygen atoms | Bacteria, archaea and eukaryotes |
| Nucleotide sugars | Monosaccharides | Bacteria, archaea and eukaryotes |
| 3'-Phosphoadenosine-5'-phosphosulfate | Sulfate group | Bacteria, archaea and eukaryotes |
| Pyrroloquinoline quinone | Electrons | Bacteria |
| Tetrahydrobiopterin | Oxygen atom and electrons | Bacteria, archaea and eukaryotes |
| Tetrahydromethanopterin | Methyl group | Methanogens |
| Ion | Examples of enzymes containing this ion |
| Cupric | Cytochrome oxidase |
| Ferrous or Ferric | Catalase
Cytochrome (via Heme) Nitrogenase Hydrogenase |
| Magnesium | Glucose 6-phosphatase
Hexokinase DNA polymerase |
| Manganese | Arginase |
| Molybdenum | Nitrate reductase
Nitrogenase |
| Nickel | Urease |
| Selenium | Glutathione peroxidase |
| Zinc | Alcohol dehydrogenase
Carbonic anhydrase DNA polymerase |