Glycogen phosphorylase isoenzyme BB (abbreviation: GPBB) is an isoenzyme of glycogen phosphorylase

Glycogen phosphorylase

Glycogen phosphorylase is one of the phosphorylase enzymes . Glycogen phosphorylase catalyzes the rate-limiting step in the degradation of glycogen in animals by releasing glucose-1-phosphate from the terminal alpha-1,4-glycosidic bond...

. This isoform of the enzyme exists in cardiac (heart) and brain tissue.

The enzyme is one of the "new cardiac markers" which are discussed to improve early diagnosis in acute coronary syndrome

Acute coronary syndrome

Acute coronary syndrome is usually one of three diseases involving the coronary arteries: ST elevation myocardial infarction , non ST elevation myocardial infarction , or unstable angina ....

. A rapid rise in blood levels can be seen in myocardial infarction

Myocardial infarction

Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...

 and unstable angina

Unstable angina

Unstable angina is a type of angina pectoris that is irregular. It is a type of acute coronary syndrome.It can be difficult to distinguish from non–Q-wave myocardial infarction.-Definition:...

.

Other enzymes related to glycogen phosphorylase are abbreviated as GPLL (liver) and GPMM (muscle).