Amino acid dipepetide frequency for Homo sapiens (Human)

Apart from single amino acid frequencies one can also calculate so called amino acid dipeptide frequency.

There is 400 possibilites (441 if we consider Xaa as additional 21st amino acid representing all non-standard or unknown amino acids). Thus, if the dipeptides would be present randomly in proteins each amino acid dipeptide should be present with 0.25% frequency. As it is not the case in the nature, for better visablity all more than expected dipepetides are marked by red, and those which are underrepresented are marked by blue in the table.

All values are presented as per milles (‰), therefore need to be multiplied by 10^-3.

For more information see sequence space article on Wikipedia.

	Ala	Cys	Asp	Glu	Phe	Gly	His	Ile	Lys	Leu	Met	Asn	Pro	Gln	Arg	Ser	Thr	Val	Trp	Tyr	Xaa
Ala	6.786AlaAla: 6.786 ± 0.028	1.358AlaCys: 1.358 ± 0.007	2.856AlaAsp: 2.856 ± 0.011	4.815AlaGlu: 4.815 ± 0.02	2.561AlaPhe: 2.561 ± 0.011	4.789AlaGly: 4.789 ± 0.018	1.532AlaHis: 1.532 ± 0.007	2.714AlaIle: 2.714 ± 0.011	3.386AlaLys: 3.386 ± 0.015	7.057AlaLeu: 7.057 ± 0.026	1.503AlaMet: 1.503 ± 0.006	1.977AlaAsn: 1.977 ± 0.008	4.256AlaPro: 4.256 ± 0.023	3.291AlaGln: 3.291 ± 0.013	3.646AlaArg: 3.646 ± 0.014	5.912AlaSer: 5.912 ± 0.034	3.754AlaThr: 3.754 ± 0.022	4.7AlaVal: 4.7 ± 0.013	0.824AlaTrp: 0.824 ± 0.006	1.47AlaTyr: 1.47 ± 0.008	0.014AlaXaa: 0.014 ± 0.0
Cys	1.198CysAla: 1.198 ± 0.007	0.657CysCys: 0.657 ± 0.008	0.982CysAsp: 0.982 ± 0.007	1.286CysGlu: 1.286 ± 0.008	0.822CysPhe: 0.822 ± 0.005	1.743CysGly: 1.743 ± 0.013	0.669CysHis: 0.669 ± 0.005	0.904CysIle: 0.904 ± 0.005	1.136CysLys: 1.136 ± 0.007	2.156CysLeu: 2.156 ± 0.012	0.421CysMet: 0.421 ± 0.004	0.787CysAsn: 0.787 ± 0.007	1.372CysPro: 1.372 ± 0.01	1.076CysGln: 1.076 ± 0.007	1.292CysArg: 1.292 ± 0.006	1.946CysSer: 1.946 ± 0.01	1.057CysThr: 1.057 ± 0.006	1.282CysVal: 1.282 ± 0.008	0.307CysTrp: 0.307 ± 0.003	0.571CysTyr: 0.571 ± 0.005	0.007CysXaa: 0.007 ± 0.0
Asp	2.921AspAla: 2.921 ± 0.014	1.02AspCys: 1.02 ± 0.007	2.625AspAsp: 2.625 ± 0.01	3.425AspGlu: 3.425 ± 0.012	2.078AspPhe: 2.078 ± 0.009	3.338AspGly: 3.338 ± 0.017	1.143AspHis: 1.143 ± 0.005	2.54AspIle: 2.54 ± 0.01	2.496AspLys: 2.496 ± 0.011	4.895AspLeu: 4.895 ± 0.016	1.104AspMet: 1.104 ± 0.006	1.645AspAsn: 1.645 ± 0.009	2.912AspPro: 2.912 ± 0.01	1.823AspGln: 1.823 ± 0.008	2.422AspArg: 2.422 ± 0.011	4.216AspSer: 4.216 ± 0.014	2.609AspThr: 2.609 ± 0.024	3.069AspVal: 3.069 ± 0.013	0.622AspTrp: 0.622 ± 0.005	1.436AspTyr: 1.436 ± 0.007	0.008AspXaa: 0.008 ± 0.0
Glu	5.25GluAla: 5.25 ± 0.019	1.455GluCys: 1.455 ± 0.013	4.499GluAsp: 4.499 ± 0.014	8.125GluGlu: 8.125 ± 0.037	2.002GluPhe: 2.002 ± 0.008	4.218GluGly: 4.218 ± 0.016	1.505GluHis: 1.505 ± 0.007	3.169GluIle: 3.169 ± 0.016	5.48GluLys: 5.48 ± 0.022	6.442GluLeu: 6.442 ± 0.025	1.72GluMet: 1.72 ± 0.008	3.175GluAsn: 3.175 ± 0.014	3.355GluPro: 3.355 ± 0.022	3.187GluGln: 3.187 ± 0.017	4.059GluArg: 4.059 ± 0.014	4.413GluSer: 4.413 ± 0.015	3.451GluThr: 3.451 ± 0.012	4.221GluVal: 4.221 ± 0.02	0.713GluTrp: 0.713 ± 0.005	1.62GluTyr: 1.62 ± 0.013	0.011GluXaa: 0.011 ± 0.001
Phe	1.888PheAla: 1.888 ± 0.01	0.893PheCys: 0.893 ± 0.006	1.628PheAsp: 1.628 ± 0.007	1.975PheGlu: 1.975 ± 0.01	1.51PhePhe: 1.51 ± 0.009	2.162PheGly: 2.162 ± 0.011	1.048PheHis: 1.048 ± 0.006	1.761PheIle: 1.761 ± 0.009	1.738PheLys: 1.738 ± 0.01	3.973PheLeu: 3.973 ± 0.016	0.77PheMet: 0.77 ± 0.005	1.298PheAsn: 1.298 ± 0.007	1.994PhePro: 1.994 ± 0.009	1.802PheGln: 1.802 ± 0.008	1.976PheArg: 1.976 ± 0.013	3.35PheSer: 3.35 ± 0.013	2.027PheThr: 2.027 ± 0.008	2.059PheVal: 2.059 ± 0.009	0.485PheTrp: 0.485 ± 0.004	1.144PheTyr: 1.144 ± 0.006	0.009PheXaa: 0.009 ± 0.0
Gly	4.5GlyAla: 4.5 ± 0.019	1.271GlyCys: 1.271 ± 0.008	3.178GlyAsp: 3.178 ± 0.018	4.234GlyGlu: 4.234 ± 0.02	2.376GlyPhe: 2.376 ± 0.011	5.035GlyGly: 5.035 ± 0.023	1.806GlyHis: 1.806 ± 0.022	2.685GlyIle: 2.685 ± 0.009	3.835GlyLys: 3.835 ± 0.019	5.897GlyLeu: 5.897 ± 0.02	1.321GlyMet: 1.321 ± 0.007	2.36GlyAsn: 2.36 ± 0.009	4.35GlyPro: 4.35 ± 0.03	2.848GlyGln: 2.848 ± 0.013	3.756GlyArg: 3.756 ± 0.014	5.833GlySer: 5.833 ± 0.02	3.65GlyThr: 3.65 ± 0.015	3.559GlyVal: 3.559 ± 0.014	0.808GlyTrp: 0.808 ± 0.006	1.714GlyTyr: 1.714 ± 0.01	0.012GlyXaa: 0.012 ± 0.001
His	1.383HisAla: 1.383 ± 0.015	0.719HisCys: 0.719 ± 0.005	0.875HisAsp: 0.875 ± 0.005	1.326HisGlu: 1.326 ± 0.006	1.055HisPhe: 1.055 ± 0.006	1.538HisGly: 1.538 ± 0.009	0.904HisHis: 0.904 ± 0.007	1.22HisIle: 1.22 ± 0.007	1.263HisLys: 1.263 ± 0.007	2.894HisLeu: 2.894 ± 0.012	0.588HisMet: 0.588 ± 0.004	0.854HisAsn: 0.854 ± 0.005	1.672HisPro: 1.672 ± 0.008	1.332HisGln: 1.332 ± 0.009	1.615HisArg: 1.615 ± 0.008	2.32HisSer: 2.32 ± 0.012	1.551HisThr: 1.551 ± 0.011	1.516HisVal: 1.516 ± 0.007	0.35HisTrp: 0.35 ± 0.004	0.789HisTyr: 0.789 ± 0.005	0.006HisXaa: 0.006 ± 0.0
Ile	2.514IleAla: 2.514 ± 0.009	1.049IleCys: 1.049 ± 0.006	1.967IleAsp: 1.967 ± 0.009	2.57IleGlu: 2.57 ± 0.013	1.845IlePhe: 1.845 ± 0.01	2.163IleGly: 2.163 ± 0.01	1.346IleHis: 1.346 ± 0.008	2.354IleIle: 2.354 ± 0.011	2.6IleLys: 2.6 ± 0.014	4.496IleLeu: 4.496 ± 0.016	0.992IleMet: 0.992 ± 0.004	1.795IleAsn: 1.795 ± 0.008	2.596IlePro: 2.596 ± 0.01	2.264IleGln: 2.264 ± 0.01	2.312IleArg: 2.312 ± 0.01	3.673IleSer: 3.673 ± 0.011	2.619IleThr: 2.619 ± 0.019	2.472IleVal: 2.472 ± 0.014	0.497IleTrp: 0.497 ± 0.004	1.328IleTyr: 1.328 ± 0.007	0.008IleXaa: 0.008 ± 0.0
Lys	3.966LysAla: 3.966 ± 0.016	1.153LysCys: 1.153 ± 0.009	3.152LysAsp: 3.152 ± 0.018	5.146LysGlu: 5.146 ± 0.021	1.682LysPhe: 1.682 ± 0.007	3.205LysGly: 3.205 ± 0.019	1.376LysHis: 1.376 ± 0.007	2.766LysIle: 2.766 ± 0.013	4.632LysLys: 4.632 ± 0.02	5.098LysLeu: 5.098 ± 0.017	1.46LysMet: 1.46 ± 0.009	2.356LysAsn: 2.356 ± 0.01	3.193LysPro: 3.193 ± 0.02	2.596LysGln: 2.596 ± 0.013	3.294LysArg: 3.294 ± 0.012	3.846LysSer: 3.846 ± 0.015	3.137LysThr: 3.137 ± 0.011	3.466LysVal: 3.466 ± 0.022	0.61LysTrp: 0.61 ± 0.006	1.555LysTyr: 1.555 ± 0.01	0.013LysXaa: 0.013 ± 0.001
Leu	6.662LeuAla: 6.662 ± 0.023	2.154LeuCys: 2.154 ± 0.012	4.672LeuAsp: 4.672 ± 0.016	7.227LeuGlu: 7.227 ± 0.028	3.286LeuPhe: 3.286 ± 0.015	5.88LeuGly: 5.88 ± 0.021	2.731LeuHis: 2.731 ± 0.012	3.782LeuIle: 3.782 ± 0.014	5.747LeuLys: 5.747 ± 0.018	10.798LeuLeu: 10.798 ± 0.037	2.018LeuMet: 2.018 ± 0.009	3.429LeuAsn: 3.429 ± 0.012	6.176LeuPro: 6.176 ± 0.035	5.803LeuGln: 5.803 ± 0.025	5.957LeuArg: 5.957 ± 0.018	7.939LeuSer: 7.939 ± 0.022	5.048LeuThr: 5.048 ± 0.016	5.444LeuVal: 5.444 ± 0.018	1.145LeuTrp: 1.145 ± 0.007	2.451LeuTyr: 2.451 ± 0.011	0.024LeuXaa: 0.024 ± 0.001
Met	1.996MetAla: 1.996 ± 0.008	0.384MetCys: 0.384 ± 0.003	1.273MetAsp: 1.273 ± 0.007	1.901MetGlu: 1.901 ± 0.009	0.713MetPhe: 0.713 ± 0.005	1.308MetGly: 1.308 ± 0.007	0.467MetHis: 0.467 ± 0.004	0.836MetIle: 0.836 ± 0.005	1.456MetLys: 1.456 ± 0.008	1.985MetLeu: 1.985 ± 0.009	0.582MetMet: 0.582 ± 0.004	0.897MetAsn: 0.897 ± 0.006	1.118MetPro: 1.118 ± 0.009	0.937MetGln: 0.937 ± 0.005	1.064MetArg: 1.064 ± 0.006	1.586MetSer: 1.586 ± 0.007	1.163MetThr: 1.163 ± 0.006	1.38MetVal: 1.38 ± 0.007	0.25MetTrp: 0.25 ± 0.003	0.546MetTyr: 0.546 ± 0.004	0.004MetXaa: 0.004 ± 0.0
Asn	2.023AsnAla: 2.023 ± 0.008	0.792AsnCys: 0.792 ± 0.006	1.49AsnAsp: 1.49 ± 0.008	2.223AsnGlu: 2.223 ± 0.011	1.444AsnPhe: 1.444 ± 0.008	2.434AsnGly: 2.434 ± 0.012	0.945AsnHis: 0.945 ± 0.005	2.088AsnIle: 2.088 ± 0.008	2.166AsnLys: 2.166 ± 0.01	3.688AsnLeu: 3.688 ± 0.014	0.891AsnMet: 0.891 ± 0.006	1.489AsnAsn: 1.489 ± 0.008	2.126AsnPro: 2.126 ± 0.008	1.665AsnGln: 1.665 ± 0.008	1.822AsnArg: 1.822 ± 0.007	3.095AsnSer: 3.095 ± 0.013	1.924AsnThr: 1.924 ± 0.007	2.174AsnVal: 2.174 ± 0.01	0.449AsnTrp: 0.449 ± 0.004	1.121AsnTyr: 1.121 ± 0.007	0.007AsnXaa: 0.007 ± 0.0
Pro	4.938ProAla: 4.938 ± 0.022	1.137ProCys: 1.137 ± 0.008	2.789ProAsp: 2.789 ± 0.012	4.529ProGlu: 4.529 ± 0.02	1.866ProPhe: 1.866 ± 0.008	5.406ProGly: 5.406 ± 0.039	1.462ProHis: 1.462 ± 0.008	1.934ProIle: 1.934 ± 0.014	2.799ProLys: 2.799 ± 0.018	5.416ProLeu: 5.416 ± 0.03	1.093ProMet: 1.093 ± 0.006	1.781ProAsn: 1.781 ± 0.008	6.183ProPro: 6.183 ± 0.039	2.889ProGln: 2.889 ± 0.014	3.422ProArg: 3.422 ± 0.014	5.897ProSer: 5.897 ± 0.025	3.192ProThr: 3.192 ± 0.018	4.028ProVal: 4.028 ± 0.035	0.714ProTrp: 0.714 ± 0.005	1.514ProTyr: 1.514 ± 0.011	0.014ProXaa: 0.014 ± 0.001
Gln	3.587GlnAla: 3.587 ± 0.017	0.943GlnCys: 0.943 ± 0.008	2.369GlnAsp: 2.369 ± 0.009	4.049GlnGlu: 4.049 ± 0.018	1.372GlnPhe: 1.372 ± 0.006	2.884GlnGly: 2.884 ± 0.012	1.304GlnHis: 1.304 ± 0.007	1.958GlnIle: 1.958 ± 0.008	2.971GlnLys: 2.971 ± 0.014	4.726GlnLeu: 4.726 ± 0.021	1.143GlnMet: 1.143 ± 0.006	1.838GlnAsn: 1.838 ± 0.009	2.898GlnPro: 2.898 ± 0.014	3.168GlnGln: 3.168 ± 0.025	2.995GlnArg: 2.995 ± 0.014	3.107GlnSer: 3.107 ± 0.013	2.3GlnThr: 2.3 ± 0.01	2.779GlnVal: 2.779 ± 0.011	0.571GlnTrp: 0.571 ± 0.004	1.127GlnTyr: 1.127 ± 0.006	0.011GlnXaa: 0.011 ± 0.001
Arg	3.836ArgAla: 3.836 ± 0.015	1.237ArgCys: 1.237 ± 0.008	2.76ArgAsp: 2.76 ± 0.01	4.038ArgGlu: 4.038 ± 0.015	1.837ArgPhe: 1.837 ± 0.008	3.669ArgGly: 3.669 ± 0.017	1.529ArgHis: 1.529 ± 0.008	2.429ArgIle: 2.429 ± 0.01	3.667ArgLys: 3.667 ± 0.012	5.43ArgLeu: 5.43 ± 0.018	1.222ArgMet: 1.222 ± 0.006	2.124ArgAsn: 2.124 ± 0.008	3.292ArgPro: 3.292 ± 0.012	2.626ArgGln: 2.626 ± 0.012	4.366ArgArg: 4.366 ± 0.017	4.265ArgSer: 4.265 ± 0.019	2.81ArgThr: 2.81 ± 0.011	3.165ArgVal: 3.165 ± 0.017	0.724ArgTrp: 0.724 ± 0.005	1.41ArgTyr: 1.41 ± 0.007	0.012ArgXaa: 0.012 ± 0.001
Ser	5.529SerAla: 5.529 ± 0.029	1.87SerCys: 1.87 ± 0.01	3.855SerAsp: 3.855 ± 0.016	5.196SerGlu: 5.196 ± 0.015	3.02SerPhe: 3.02 ± 0.011	5.646SerGly: 5.646 ± 0.022	2.12SerHis: 2.12 ± 0.009	3.16SerIle: 3.16 ± 0.012	4.022SerLys: 4.022 ± 0.013	8.192SerLeu: 8.192 ± 0.026	1.643SerMet: 1.643 ± 0.008	2.674SerAsn: 2.674 ± 0.011	6.102SerPro: 6.102 ± 0.028	3.914SerGln: 3.914 ± 0.013	4.574SerArg: 4.574 ± 0.016	9.65SerSer: 9.65 ± 0.052	4.807SerThr: 4.807 ± 0.052	4.905SerVal: 4.905 ± 0.015	1.142SerTrp: 1.142 ± 0.008	2.037SerTyr: 2.037 ± 0.008	0.019SerXaa: 0.019 ± 0.001
Thr	3.826ThrAla: 3.826 ± 0.014	1.288ThrCys: 1.288 ± 0.009	2.557ThrAsp: 2.557 ± 0.02	3.579ThrGlu: 3.579 ± 0.015	2.086ThrPhe: 2.086 ± 0.009	3.863ThrGly: 3.863 ± 0.04	1.317ThrHis: 1.317 ± 0.008	2.368ThrIle: 2.368 ± 0.012	2.636ThrLys: 2.636 ± 0.015	5.309ThrLeu: 5.309 ± 0.015	1.126ThrMet: 1.126 ± 0.006	1.729ThrAsn: 1.729 ± 0.008	3.902ThrPro: 3.902 ± 0.037	2.321ThrGln: 2.321 ± 0.01	2.493ThrArg: 2.493 ± 0.01	4.955ThrSer: 4.955 ± 0.049	3.326ThrThr: 3.326 ± 0.041	3.831ThrVal: 3.831 ± 0.019	0.731ThrTrp: 0.731 ± 0.007	1.402ThrTyr: 1.402 ± 0.008	0.01ThrXaa: 0.01 ± 0.0
Val	4.22ValAla: 4.22 ± 0.014	1.385ValCys: 1.385 ± 0.008	2.891ValAsp: 2.891 ± 0.01	3.887ValGlu: 3.887 ± 0.019	2.312ValPhe: 2.312 ± 0.01	3.341ValGly: 3.341 ± 0.011	1.53ValHis: 1.53 ± 0.008	2.892ValIle: 2.892 ± 0.014	3.357ValLys: 3.357 ± 0.019	6.114ValLeu: 6.114 ± 0.019	1.331ValMet: 1.331 ± 0.006	2.221ValAsn: 2.221 ± 0.01	3.678ValPro: 3.678 ± 0.021	2.723ValGln: 2.723 ± 0.009	2.997ValArg: 2.997 ± 0.012	4.986ValSer: 4.986 ± 0.022	4.094ValThr: 4.094 ± 0.045	3.935ValVal: 3.935 ± 0.018	0.71ValTrp: 0.71 ± 0.005	1.578ValTyr: 1.578 ± 0.007	0.012ValXaa: 0.012 ± 0.001
Trp	0.817TrpAla: 0.817 ± 0.005	0.26TrpCys: 0.26 ± 0.003	0.656TrpAsp: 0.656 ± 0.005	0.827TrpGlu: 0.827 ± 0.006	0.441TrpPhe: 0.441 ± 0.004	0.744TrpGly: 0.744 ± 0.006	0.303TrpHis: 0.303 ± 0.003	0.546TrpIle: 0.546 ± 0.004	0.82TrpLys: 0.82 ± 0.004	1.225TrpLeu: 1.225 ± 0.007	0.324TrpMet: 0.324 ± 0.003	0.554TrpAsn: 0.554 ± 0.005	0.555TrpPro: 0.555 ± 0.005	0.548TrpGln: 0.548 ± 0.004	0.755TrpArg: 0.755 ± 0.005	0.917TrpSer: 0.917 ± 0.006	0.698TrpThr: 0.698 ± 0.006	0.689TrpVal: 0.689 ± 0.005	0.208TrpTrp: 0.208 ± 0.002	0.336TrpTyr: 0.336 ± 0.004	0.004TrpXaa: 0.004 ± 0.0
Tyr	1.346TyrAla: 1.346 ± 0.007	0.641TyrCys: 0.641 ± 0.006	1.261TyrAsp: 1.261 ± 0.007	1.696TyrGlu: 1.696 ± 0.01	1.173TyrPhe: 1.173 ± 0.006	1.649TyrGly: 1.649 ± 0.009	0.725TyrHis: 0.725 ± 0.004	1.345TyrIle: 1.345 ± 0.007	1.485TyrLys: 1.485 ± 0.012	2.56TyrLeu: 2.56 ± 0.012	0.59TyrMet: 0.59 ± 0.003	1.063TyrAsn: 1.063 ± 0.007	1.264TyrPro: 1.264 ± 0.007	1.278TyrGln: 1.278 ± 0.007	1.617TyrArg: 1.617 ± 0.007	2.153TyrSer: 2.153 ± 0.01	1.429TyrThr: 1.429 ± 0.01	1.511TyrVal: 1.511 ± 0.007	0.363TyrTrp: 0.363 ± 0.003	0.916TyrTyr: 0.916 ± 0.006	0.005TyrXaa: 0.005 ± 0.0
Xaa	0.017XaaAla: 0.017 ± 0.001	0.005XaaCys: 0.005 ± 0.0	0.011XaaAsp: 0.011 ± 0.001	0.016XaaGlu: 0.016 ± 0.001	0.009XaaPhe: 0.009 ± 0.001	0.015XaaGly: 0.015 ± 0.001	0.005XaaHis: 0.005 ± 0.0	0.009XaaIle: 0.009 ± 0.0	0.012XaaLys: 0.012 ± 0.001	0.02XaaLeu: 0.02 ± 0.001	0.005XaaMet: 0.005 ± 0.0	0.009XaaAsn: 0.009 ± 0.0	0.012XaaPro: 0.012 ± 0.001	0.009XaaGln: 0.009 ± 0.001	0.014XaaArg: 0.014 ± 0.001	0.017XaaSer: 0.017 ± 0.001	0.011XaaThr: 0.011 ± 0.0	0.01XaaVal: 0.01 ± 0.001	0.002XaaTrp: 0.002 ± 0.0	0.005XaaTyr: 0.005 ± 0.0	0.0XaaXaa: 0.0 ± 0.0

Statistics based on 100100 proteins (40284240 amino acids)

Note: The error has been estimated with the bootstraping (x100) at the protein level

Above dipeptide statistics (among other stats for this proteome) you can download from this CSV file

Reference: Kozlowski LP. Proteome-pI 2.0: Proteome Isoelectric Point Database Update. Nucleic Acids Res. 2021, doi: 10.1093/nar/gkab944

Contact: Lukasz P. Kozlowski

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