Amino Acids: Histidine

HISTIDINE HIS, H

CHEMICAL STRUCTURE

CHEMICAL SHIFTS

Standard chemical shifts of random extended chain structures:

¹H^a	¹³C^a	¹⁵N^b
NH: 8.41 HA: 4.63 HB: 3.26, 3.20 H2: 8.12 H4: 7.14	CO: 172.6 CA: 53.7 CB: 28.0 C2: 135.2 C4: 118.7 C5: 130.3	N: 119.1

a) from 86BOOK1: b) from 91JMB311-222

More info in:

¹H chemical shifts of amino acids

¹³C chemical shifts of amino acids

Average ¹HA, ¹HN and ¹⁵N chemical shifts in random coil

IDENTIFICATION

Easy spin system identification from:

HA-HB cross-peak in a COSY-DQF experiment.

Typical AMX pattern in a TOCSY experiment.

SECONDARY STRUCTURE

Standard average chemical shift values used in determination of secondary structure by means of the CSI method:
HA: 4.63
CA: 55.5
CO: 174.9
Thus:
          HELIX           B STRAND          COIL
             CA      CO       CA      CO           CA      CO
            58.5    176.7     55.1    173.6      55.5    174.9
More info in: ¹³CA and ¹³CO chemical shifts according to secondary structure.

OBSERVATIONS

RELATED TOPICS