BIOC12H3 Lecture Notes - Lecture 3: Isoelectric Focusing, Thyroid Hormones, Histamine
Document Summary
Tyrosine [y] has no h group, slightly less hydrophobic in positioning. Each of them absorb uv light within uv spectrum. > yes we can however if you have a protein with no tryptophan or tyrosine, we make it a very low. 280 or we may not get any absorbance at all: protein quantification more difficult than dna and rna. Sulfur protected by ch3 group in met so can"t use s to interact unlike cysteine. Generally met can"t interact w/ anything but is first amino acid, but not always after maturation. Met not in high number in proteins because it"s used as a location aa. Cys can form hydrogen bonds with n and o, can lose a proton, and is a weak acid. Cys can form disulfide bonds is very important in maintaining integrity of protein in extracellular space ie. in secretory pathway. Thr has 2 chiral centres therefore 4 stereoisomers. L & d threonine and l & d allothreonine.
